UNIVERSITY OF KIGALI
School of Law
P.O Box 2611 Kigali
LEGAL THEORY (Legal
philosophy)
By Dr. Nkubito William
Mar. 2025
I. INTRODUCTION
1. Definition of philosophy
Philosophy is the study of general and
fundamental problems, such as those
connected with reality of the things, existence
of the things, knowledge, values, reason,
mind and language.
It is a study of the fundamental nature of
knowledge, reality/authenticity and existence.
When considered as an academic discipline
philosophy studies the theoretical basis of a
particular branch of knowledge or experience.
 The word "philosophy" comes from the Ancient
Greek (philosophia), which literally means "love of
wisdom".
 That is, ‘’Philos’’ = Love and ‘’Sophia’’ =
Wisdom’’.
 Love itself evokes absence of something;
something that is lacking: People love what they
don’t have: Loving an object means desiring it,
and nobody would desire something he/she
already has. If someone says that h/she loves
something that he/she has, it actually means
he/she desires to continue having it (Socrates).
 Whilst Wisdom is the acquisition of truth (a wise
person can usually recognize and apply the truth).
3. Methods of Philosophy
 Rational ( or abstract method):
 Rationalism is the idea that knowledge can be acquired
through reason alone. In rationalism, truth can be
found with deduction, that is, applying principles to
draw conclusions.
 In philosophy, rationalism is the view that "regards
“reason” as the chief source and test of knowledge. or
"any view appealing to reason as a source of
knowledge” often in contrast to other possible sources
of knowledge such as faith, tradition, or sensory
experience.
 Activity/ criticisms: Activity of criticism about all
aspects or reality. This activity is different from
observation/ description view.
 Questioning: (Why man is wise? Why universe is
moving? (Philosophy asks more than it answers
to its questions).
 Discussions: Discussions with rational
arguments.
 Logic: reasoning and argumentation are the
predominant methods used.
 Example of Classic philosophical questions
consists of: “Is it possible to know anything and to
prove it? What is most real?
 Philosophers also pose more practical and
concrete questions such as: Is there a best way to
live? Is it better to be just or unjust? Do humans
have free will?
4. Content of philosophy
Historically "philosophy" encompassed any
body of knowledge. From the time of
Ancient Greek philosopher Aristotle to the
19th century, "natural philosophy"
encompassed astronomy, medicine, and
physics.
 For example, Newton's 1687 Mathematical
Principles of Natural Philosophy later
became classified as a book of physics.
- A growth of modern research in
universities in 19th century:
Research at universities which led academic
philosophy and other disciplines to
professionalize and specialize.
Development of separate academic
disciplines from philosophy
In the modern era, some investigations that
were traditionally part of philosophy became
separate academic disciplines, including
psychology, sociology, linguistics, and
economics. …
Other investigations closely related to art,
politics, or other pursuits remained part of
philosophy. For example, is beauty
objective or subjective?
5. Divisions (sub-fields) of academic philosophy
 Philosophy has several branches of knowledge,
among others:
 Metaphysics: The study of the reality and being/
realism/authenticity of a phenomenon. It refers to an
idea, doctrine, or posited reality outside of human
sense perception. In modern philosophical
terminology, metaphysics refers to the studies of
what cannot be reached through objective studies of
material reality.
 Epistemology: From the Greek words episteme,
meaning “knowledge,” and logos/logia, meaning
“study of”.
Hence, epistemology is the study of knowledge. It
focuses on what knowledge is as well as what
types of knowledge there are.
It deals with how and from which sources
knowledge is gathered.
It is the theory of knowledge, especially with
regard to its methods, validity, and scope, and the
distinction between justification, belief and
opinion.
 Axiology: (Theory of Value). Studies what is worth
or value of something. It is a philosophical study of
goodness, or value.
The two major subdivisions of axiology are
aesthetics and ethics.
Aesthetics is concerned with the nature of beauty and
taste.
Aesthetics is the study of the importance of beauty in
our lives and our actions.
Ethics is concerned with the nature of right and
wrong.
 Logic: Science which studies argumentation and
reasoning.
 Logic is the study of correct reasoning. It includes
both formal and informal logic.
 Formal logic is the study of deductively valid inferences
or logical truths.
 It examines how conclusions follow from premises due
to the structured arguments alone, independent of their
topic and content.
 Informal logic is associated with critical thinking,
and argumentation theory.
 It examines arguments expressed in natural
language while formal logic uses formal
language.
 Ethics: Moral principles that govern a person's
behaviour or the conducting of an activity.
 Cosmology: The science of the origin and
development of the universe. It is a branch of
philosophy dealing with the origin and general
structure of the universe, with its parts, elements,
and laws.
 Political philosophy: studies government ruling
 It is the philosophical study of government,
addressing questions about the nature, scope,
and legitimacy of public agents and institutions
and the relationships between them.
 Its topics include politics, justice, liberty, rights,
law, and the enforcement of laws by authority:
what they are, if they are needed, what makes a
government legitimate, what rights and freedoms
it should protect, what form it should take, what
the law is, and what duties citizens owe to a
legitimate government (if any), and when it may
be legitimately overthrown (if ever).
5.1. Ethics and phylosophy
Also called moral philosophy, “ethics” is a
discipline concerned with what is morally good
and what is morally bad as well as morally right
and wrong. It is applied to the theory of moral
values or principles.
 Some questions of ethics and philosophy include
for example:
 How should we live? Shall we aim at happiness,
or simply at knowledge? If we choose happiness,
will it be our own or the happiness of all?
 And the more particular questions that we
face: is it right to be dishonest in a good
cause?
 Can we justify living in luxuriousness while
elsewhere in the world people are starving?
 Is going to war justified in cases where it is
likely that innocent people will be killed?
(lesser evil?)
 What are our obligations, if any, to the
generations of humans who will come after
us and to the non human animals with
whom we share the planet?
5.2. Knowledge and philosophy
 The term "knowledge" can refer to a theoretical
or practical understanding of a subject. It can be
implicit (as with practical skill or expertise) or
explicit (as with the theoretical understanding of
a subject); formal/systematic or informal.
 But the English word “knowledge” combines
various meanings that are distinguished in other
languages: for instance, the verb “to know” can
be translated into French either as “connaître”
or as “savoir” which contains knowledge.
6. Legal philosophy (philosophy of law)
Watch
https://www.youtube.com/watch?v=4kw58Vm3lFM
:2min24 secs-
 The "Philosophy of Law" is a term which comes
from the Principles of philosophy of Law .
 The philosophy of Law is not a branch of Law,
but of Philosophy.
 The Philosophy of law is concerned with the
question of what is the relationship between
Philosophy and law.
 Philosophy of law is connected to the theory of
law (or Legal theory)
 Here, we must go back to each of these two concepts
to understand this relationship. What is philosophy?
What is law?
 The philosophy of law, also called jurisprudence, is a
branch of philosophy that investigates the nature of
law, especially in its relation to human values,
attitudes, practices, and political communities.
 The word jurisprudence derives from the Latin term
“juris prudentia”, which means "the study, knowledge,
or science of law." In some countries like the US, Italy
etc, jurisprudence commonly means the philosophy of
law.
 ‘jurisprudence’:
 juris = of law; Prudens = skilled, caution, prudence,
balance
 Philosophy of law as expression, it dates back
to 1821.
 As a reflection, law was born with the birth of
philosophy.
 Philosophy = reflection on the meaning of life,
man etc.
 Law: a set of norms/rules, which regulates
human behaviour
 Philosophy of law studies ‘why’/what law (not
‘how’ law is)
 Philosophy of law studies reflection/ clarification
on the meaning and the essence/nature of law
(foundation, critical justification)
 The philosophy of law defines law through three
points of view: historical, descriptive and critical:
 The historical point of view focuses on the origin and
evolution of law in different human Societies.
 The descriptive point of view is concerned with the
search of explanation of law by seeking the various
meanings of law and its role in the society.
 The critical angle is concerned with the question of
the significance of law.
 From this perspective, it will be a question of looking
at law as a system of norms that aims at the
sanctions according to the choice established by the
authority that established these laws.
a. Foundation (raison d’être)
The clarification of the basis/foundation of law.
The preliminary question:
why does law exist rather than the absence of law?
why is it better that law exists rather than the
absence of law?
b. Critical justification
To criticise means “to express a judgement”.
The analysis of a juridical norm that exists (in force)
Asking the question: is this law acceptable or
unacceptable; just/unjust? = de lege lata.
c. Formulation
 The planning of (possible) future law,
investigating how the law must or should be in
order to draft a “better” law than the existing one
(if acceptable) and to formulate new norms
where necessary or absent
= what the law ‘ought’ to be (de lege ferenda)
 Thus, we distinguish on one hand the ‘analytical’
jurisprudence: scientific analysis of legal
structures and concepts; and on the other hand,
the ‘normative jurisprudence’: knowledge of
nature, place, role of law within society.
Analytic Jurisprudence
 The principal objective of analytic jurisprudence
has traditionally been to provide an account of
what distinguishes law as a system of norms from
other systems such as ethical norms, religious
norms etc.
 The question that has received the most attention
from philosophers of law is What is law?
 According to H.L.A. Hart in his book “The concept
of law”( 1961), law is essentially a system of
primary social rules that guide the conduct of
law's subjects(people), and how disputes are to
be adjudicated.
Several schools of thought (theorists)have
provided rival answers to the question “what is
law”. The most influential of doctrines are
natural law and positive law theories.
 Natural law theory asserts that there are laws
that are inherent in nature, to which enacted
laws should correspond as closely as
possible.
 This view is frequently summarized by the
maxim: an unjust law is not a true law, in
which 'unjust' is defined as contrary to natural
law. Ex: right to life
 Legal positivism is the view that the law is defined
by the social rules or practices that identify certain
norms as laws. One of the early positivists was
Jeremy Bentham, whose views influenced a major
positivist thinker of the nineteenth century, that is
John Austin:
 «Law must be based on social rules,cultures and
practices.Laws are those rules voted by the
parliament»
 Legal positivism:
https://www.youtube.com/watch?v=ATtqAjOkqwk
https://www.youtube.com/watch?v=d6JYlhz0
Q-k
Law and morality (connection)
 A study of connection between law and morality
can be made from three angles:
- Morality as basis of law;
- Morality as a test (positive) law;
- Morality as the end of law.
 Morality as basis of law
 In early stages of the society, no distinction was
made between law and morality.
 All the rules originated from the common source
and the sanction behind them was of the same
nature (mostly supernatural fear)
 When the state came into existence, it picked up
some of those rules which were important from
the society’s point of view and the observance of
which could be secured by it.
 The state put its own sanctions behind these
rules and enforced them. These rules therefore
were called Law.
 Law and morals have common origin but diverge
in the course of their development.
 Thus, as the law and morals have emerged from
the same stock, many rules are common to
both.(e.g. the prohibition of killing or stealing)
 Morality as the test of law
 A number of jurists have contended that law must
conform to the morality.
 This view was supported by Greeks and Romans.
For Romans, Law to some extent was made to
conform to “natural law” which was based on
certain moral principles. As a result, “jus civile” was
transformed in “jus gentium” (peoples’ rights).
oThe term jus civile, meaning “civil law,” was
used in ancient Rome to distinguish the law
found exclusively in the city of Rome from the
jus gentium, the law of all nations, found
throughout the empire.
 Most of ancient jurist, however, expressed their views in
a spirit of compromises and attached sanctity to legal
rules. They said that law, even if it is not in conformity
with morals, is valid and binding.
 During the Dark Ages (late 5th to the 10th century),
Christian Fathers preached forcefully that law conform to
Christian morals, and that any legal rule that is contrary
to morals is invalid.
 In the 17th and 18th centuries when the “natural law”
(which was based on some moral principles) was at its
highest, it was contended that law (positive) must be in
conformity with natural law.
 They said that any law which does not conform to the
natural law must be invalidated and the government that
adopts it should be overthrown.
 It was this theory which inspired the French revolution.
In modern times, such views of requirement
that the law must conform to the morality and
otherwise it would not be binding are no
longer heard.
However, to a great extent, law conforms to
morals: there are a number of factors which
secure the obedience to the enacted law. The
conformity of law to morality is among the
important factors.
 Morals and the end (objective/aim) of law
 Morals have been considered to be the end of
law.
 A number of jurists have defined law in terms
of justice. According to them, the objective of
law is to secure justice. Justice in its popular
sense is much based upon morals.
 According to analytical jurists, any study of the
ends of law falls beyond the domain of positive
law. Thus, any obligation and right end to
promote human welfare, to yield what man
does actually find to be of value.
Legal doctrines
 Naturalism (Jus naturalism): Is a legal doctrine
based on natural law (reason and good conscience).
 Positivism: Is a legal doctrine based on the positive
law (scientific method that considers law and
evidences as social facts observables in the society).
 Realism jurisprudence: The view according to which
the law should rely on empirical evidences, should be
tested against neither from nature nor from the will, but
from most widespread, repeated and frequent social
evidences of behaviours.
 The philosophy of realism believes that the external
world has a real existence and can be accessed
through human observation and experience.
o Natural law
Natural Law is defined as a body of
principles revealed by nature or reason or
God. It emanates from the source superior
to any human authority (the sovereign).
Natural law is a universal, obligatory set of
rules for action, legislated by God/or the
nature.
Natural law is based on reason and good
conscience which measures what man
should do or should not do.
Characteristics of natural law include:
 Origin: nature
 Space: universal law, everywhere
 Time: unchangeable (it is the same,
cannot be changed by man)
o Positive law
From the term “positum”, past participle of
‘ponere’ (to place, issue, posit): it therefore
means law that is ‘issued’, posited.
Characteristics of positive law include:
 origin: conventional (or artificial); it derives
from the will of whoever imposes the law.
 space: particular, a certain group of
individuals, and is in force in a certain political
community
 time: changeable law, contingent (variable)
o Real law (realism)
 "Real law" (the ‘living’ law): can refer to the
practical application and enforcement of legal
principles, distinct from abstract legal theory or
ideals.
 Origin: neither from nature nor from the will, but
from most widespread, repeated and frequent
social behaviour (habits and customs, needs or
interests); the application of laws by judges =
customary law, precedents
 Space: a certain social context
 Time: a specific period dynamic and variable law
7. Methodology of philosophy
Philosophy is not learning things by heart,
neither is it meant to accumulate knowledge.
It is first and foremost to study how people
have constantly been questioning themselves
and their surroundings.
The aim is to discover the significance of
realities and their dynamics. As such,
questions asked by philosophers are directed
towards the meaning of things hence the
WHY?
 This question should not lead to useless criticism
but rather to the ultimate explanation of things
(realities and their dynamics).
• Reality here means the sum or aggregate of all that is real or
existent within the universe, as opposed to that which is only
imaginary, nonexistent or non-actual.
 This does not mean that a philosopher knows
everything, although this is the ideal.
 We should only retain what is universally
acceptable.
 The kind of knowledge a philosopher retains is
that one that is systematic; not subjective but
objective, not private but universal.
8. The subject matter of philosophy
 Philosophy is concerned with questions of
fundamental importance about reality: man, nature,
the absolute.
 In most common usage, the absolute is a perfect,
self-sufficient reality that depends upon nothing
external.
 For example, Aristotle claims that time is not a kind
of change, but that it is something dependent on
change. He defines it as a kind of 'number of
change' with respect to “the before and the after”. It
is argued that this means that time is a kind of order
(not, as is commonly supposed, that it is a kind of
measure).
 The aim is not to re-examine, unnecessarily,
what has already been solved by other sciences,
although we might question some of their
underlying assumptions and examine the
deepest relevance and significance of some of
their conclusions.
9. Philosophy vs. other sciences
 The scientific method of research for other sciences
is observation and the central question is how?
 While the methodology in philosophy is reasoning
and the central question is why?
 While other sciences deal with matter, philosophy
transcends it as to reach the origin/essence of reality.
 Matter is anything that takes up space and can be
weighed. In other words, matter has volume and
mass.
 Necessarily, therefore, by virtue of the methodology
of research, other sciences start on bodies/data and
end on that. This renders other sciences partial, by
methodology.
 Other sciences are more interested in
constructing while philosophy is interested in
reflection.
 This is the reason why certain sciences might
remain ignorant of what they have constructed in
terms of effects and consequences e.g. the
nuclear weapon question.
 Other sciences operate in time and space. This
makes them less speculative but philosophy
goes beyond time and space: Philosophy
transcends “what is”, to what “will be” e.g. about
man, philosophy looks at man as a being beyond
time and space.
 Philosophy investigates things. Not by using lab
instruments or investigative tools, neither on the
basis of supernatural revelation, otherwise it
becomes theology. It is based on the human
reason or the unaided reason.
 Philosophy pursues questions in every
dimension of human life, and its techniques
apply to problems in any field of study or
endeavor.
 It is from the above ground that sometimes
philosophy is accepted as a super science
although it remains a domain that needs other
sciences.
10. Philosophy and Myths
 Generally accepted explanation of a
phenomenon in a given society.
 Myth, does not aim at giving a scientific truth
of the concerned phenomenon or
phenomena. However, some authors
generally agree that myths are more than
false stories.
According to Kevin Schilbrack’s thesis, it is
correct to describe myth as `true history,' in
the sense that myths are always considered
to be true by those who embrace them.
Myth is a common phenomenon.
 It can be religious e.g. in the holy books or
in traditional religions, it could be political
e.g. under monarchy, it is a general myth
that kings are born with unique feature; a
myth could be social, etc.
Any myth, whether religious, political, social,
etc. is retro ejection or projection of a
people’s experience with an intention to
convey a deeper meaning of phenomena.
This is why myths change with time, even
within the same society – for example,
explaining a people’s origin, if people are
living an experience of unity, they will have a
myth of their origin that will convey a sense of
unity while the contrary experience will be
represented by a divisive (division) myth of
origin.
 Because myths express a people’s reflection
and wisdom in front of a given issue, myths
cannot be taken for granted by a philosopher.
10. Historical perspective
 Seeking the meaning of law through great legal
philosophers in history.
 Among others: Thomas Aquinas, Thomas Hobbes, J.
Jacques Rousseau, Montesquieu, Emmanuel Kant,
Hans Kelsen, Ronald Dworkin.
o Thomas Aquinas and Natural Law:
 He distinguishes divine law/natural law and manmade law (positive law)
 What is very important to him is justice based on the
natural law.
 Natural law is a law that is inherent to nature of beings
 This law is at the basis of human rights.
o Thomas Hobbes (1588-1679): Law as a social
contract.
 Hobbes Conception: Nature is hostile.
 His book: “Leviathan” means a mythical animal
that is given the hostility and domination by
jungle, without justice. So, the society created
the order by introducing law to face this animal.
 Necessity of doing a social contract with aim to
render individual freedoms and rights to common
will in order to gain security and collective order
and other values (harmony, stability, authority
etc.).
 Social contract is the origin of law and political authority
and the State.
 Law is a kind of contract between citizens and authority.
 Constitution is a kind of social contract law. It is
elaborated as common acceptance and established by
referendum.
 Thomas Hobbes in his theory had the thesis according
to which “everything that is at all, is essentially a natural
being.
 While acknowledging the existence of a supernatural
being, Thomas Hobbes primarily grounded his political
and moral philosophy in natural human behavior and the
pursuit of self-preservation, rejecting the notion that
supernatural revelation should dictate political authority
 The idea of ruling nature is extended by Hobbes
to the inner-human nature. He equates human
nature with the animal world: a human is like
wolf to another human, homo homini lupus.
 For Hobbes, law was the primary instrument of a
sovereign by which to serve the ends of
government, which were principally peace and
the personal security of all its citizens.
 He developed the idea that government which
ruled effectively by law is the only bulwark (or
weapon) against anarchy or, as he famously put
it, “a war of all against all.”
 Hobbes’s philosophy of law is in part an
account of what law must be like in order to
serve that function.
 Many scholars credit Hobbes as the founder of
legal positivism, the dominant philosophical
theory of law since the 17th century.
 However, while Thomas Hobbes is best known
for his political philosophy and social contract
theory, he can be considered a naturalist in the
sense that he believed in a natural order and
that everything, including human nature, could
be understood through naturalistic principle.
11. Western philosophy
 The birthplace of philosophy was the seaport town
of Miletus, located across the Aegean Sea from
Athene, on the western shores of Ionia in Asia
Minor, and for this reason the first philosophers are
called either Milesians or Ionians.
 This was because of the prosperous trade in this
area and their organized communities.
 Then people started wondering and thinking not
only about their social systems but also the entire
universe i.e. giving reasoned explanations instead
of the religious explanation of the time.
SOURCES OF LAW BASED ON PHILOSOPHICAL
THEORIES (DOCTRINES)
I. NATURAL LAW THEORY
 The theory of natural law has first been introduced by
the Ancient Greek thinkers, Socrates, Plato and
Aristotle purporting that the law existed for the purpose
of facilitating the pursuit of the good life, by members
of the community.
 For Aristotle for example, the law could only be fully
understood in terms of its purpose.
 The Roman, Orator Cicero (106-43 BC), contended
that positive law ought to be assessed against the ‘true
law’ which can be accessed through ‘right reason’ as
this law is in ‘agreement with nature’ and the eternal
law of God.
1.1.Meaning
 The theory of natural law believes that our laws
should be based on morality and ethics, what is
inherently correct.
 The theory of natural law, ‘jus naturalism as a bidimensional/dualistic conception of law:
a) Law cannot be reduced only to positive law. Natural
law is the law that man does not produce, but
discovers and finds in nature (‘given’).
b) The existence of a law ‘before’, ‘beyond’ and ‘above’
positive law. Nature is a dimension of reality that
precedes and transcends/surpasses man.
 Nature is the horizon in which man finds himself.
 The natural law doesn’t deny the existence and
the juridical importance of positive law, but it
denies its exclusiveness;
 Natural law is the ‘unwritten law’ ; it is a ‘point of
intersection between law and morals.’
 Its obligatoriness/binding force is justified in
itself (objectively) independently of the formal
ruling of the legislator or of the judge’s decision.
 Natural law is “discovered” by humans through
the use of reason and choosing between good
and evil.
 It finds its power in discovering certain universal
standards in morality and ethics.
1.2. Characteristics
a) The reference to nature
 Knowledge or divine will, grasped/seized by
human reason.
 As an objective limitation to the subjective will of
man.
b) The connection between law and morals:
 Natural law includes (implicitly or explicitly) a
reference to ethics (values; good/evil).
c) The reference to justice (give each man his own):
equality, fairness, equity.
1.3. Theory of Natural law within time
 Natural law in Ancient times (VI BC – II AD)
 Natural law in Middle ages (II – XIV)
 Natural law in Modern age (XIV-XVIII)
 Natural law in Contemporary period (XIX: till
today)
A. NATURAL LAW IN ANCIENT TIMES
The idea of natural law began with ancient
Greeks conception of a universal governed
in every particular by ‘eternal’, ‘immutable’
law and in their distinction between what is
just by nature and just by convention.
Aristotle (384-322 a.C.)
Aristotle (often said to be the father of natural
law) believes that everything on this earth has
a goal or a purpose. According to him “Every
art aims for a good, as does every inquiry,
every action, every choice.”
For Aristotle, everything has a final end or
purpose and everything aims at some good.
In his metaphysics, Aristotle claims that there
must be a separate and unchanging being
that is the source of all other beings.
 He holds that it is only by becoming excellent that one
could achieve eudemonia, - a sort of happiness or
blessedness that constitutes the best kind of human life.
 “all beings by their nature have within themselves
inclinations [or dispositions/feelings] which direct them to
the end which is proper to them” (end = good)
 Aristotle argued that every being, whether a human,
animal, or plant, has a natural "nature" or "form" that
dictates its purpose and potential.
 This "nature" manifests as inclinations or dispositions,
which are internal forces that drive beings towards their
specific "end" or "telos
 Aristotle is credited with developing the first theory of
Natural Law, suggesting that certain principles of justice
are inherent and universal, applicable to all people and
communities.
 Aristotle believed in a "rule of law" where society
should be governed by just, clear, and impartial laws,
rather than arbitrary power, and that law should be an
expression of reason, promoting the "perfect
community."
 Aristotle held that what was “just by nature” was not
always the same as what was “just by law,” that there
was a natural justice valid everywhere with the same
force and “not existing by people's thinking this or that,”
and that appeal could be made to it from positive law.
 Natural law = what is just at all times and in all places
independently of the fact that it has been
decreed/adopted/legislated (‘just by nature’ and ‘legal
just’)
Aristotle’s best known work on ethics is the
Nicomanchean Ethics.
The main idea of Aristotle's Nichomachean
Ethics is eudaimonia, sometimes
translated as ‘true happiness or the highest
good that humans seek.
However, a better way to think of what
Aristotle meant by this Greek term is the
highest good that humans seek.
 The unjust has been divided into the unlawful
and the unfair, and the just into the lawful and
the fair.
 But since unfair and the unlawful are not the
same, but are different as a part is from its
whole (for all that is unfair is unlawful, but not
all that is unlawful is unfair), the unjust and
injustice in the sense of the unfair are not the
same but different from the former kind”.
“Justice is a state of mind that encourages
man to perform just actions” just = lawful, fair.
Natural justice “is set by nature, which renders
it immutable and valid in all communities”
 Conventional justice “comprises rules devised
by individual communities to serve their needs”
 Conventional justice is subject to change
(depending on the form of government), and is
subordinate to natural justice.
 Natural justice: Every person has the right to
be treated fairly, they should not be subjected
to arbitrary or unjust treatment.
Throughout his writings, Aristotle did not
teach that the Greek gods or religion
controlled the world and its people. Instead,
his observations led him to conclude that
nature was purposeful and driven by natural
laws that human reason could discover.
These natural laws provided a way to explain
the world and the place of humans within it.
Aristotle and the Politics……
 Aristotle does not completely exclude positive
law, but preaches that positive law draws from
natural law.
 "man is by nature a political animal." = people
were naturally destined to live in groups, which
required some sort of ruler or government.
 According to Aristotle, only by living in a
community "to secure the good life" could human
beings achieve such virtues as courage, honesty,
and justice.
 However, the rule to regulate this must appeal to
the natural law.
B. NATURAL LAW DURING THE MIDDLE
AGES (MEDIEVAL/ROMAN PERIOD)
This is the period in Europe when the
Catholic Church had absolute power.
Hence the main occupation here is
theology. Thinkers of the time opted for
Theology either out of conviction or out of
fear of death and or condemnation.
Any ‘rebel thinker’, was often burnt to death
in the famous inquisition.
This is the reason why the famous thinkers of
this period are mostly saints e.g. Anselm,
Boniface, Augustine, Thomas Aquinas, etc.
The most comprehensive philosopher of the
time is Thomas Aquinas.
During the Middle Ages, natural law was
primarily theological in form.
It was an integral part of religious doctrine:
For example in the teaching of Thomas
Aquinas, natural law is the concrete
expression of divine reason guiding the world
and the basis of law created by the state.
Marcus T. CICERO (106 – 43 BCE):
 Although Cicero was a legal practitioner and was
versed in the positive (human-enacted) law of
the Roman state, he sought to situate it in
relation to what he considered objective moral
truths, which he also called “laws”.
In his work De republica (On the Republic), he
held:
 “True law is right reason in agreement with nature…to curtail
[restrict] this law is impious [sinful], to amend it illicit, to
repeal it impossible…nor will it be one law at Rome and a
different one at Athens, but one and the same Law, eternal
and unchangeable.
 “Those who formulated wicked and unjust statutes
for nations, thereby breaking their promises and
agreements, put into effect anything but [natural]
laws.”
 According to Cicero, the nature of law must be
sought from human nature:
 "Law is the highest reason inherent in nature, which
commands what ought to be done and forbids the
opposite."
 Thus, natural law is the guide for right and wrong in
human affairs.
 When this same reason is secured and completed in
the human mind, it is law.
 Natural law = rational natural law (or right
reasoning/recta ratio)
 Through reason man can know the laws of
nature which must guide him; positive laws must
be founded on natural laws.
 «true law is right reasoning in agreement with
nature: it is of universal application, unchanging
and everlasting.»
 Justice = the constant and perpetual wish to
render everyone his due (Corpus Juris Civilis)
 Precepts/Principles of natural law: to live
honestly, not to injure others, to give everyone
his due.
 The State exists to uphold laws which are
in harmony with the universal principles of
nature. If a state does not uphold right
reason in agreement with nature, it is not a
state.
St. Thomas Aquinas (1225-1274)
 Thomas Aquinas is known to be the greatest
theologian-philosopher in medieval time.
 As a medieval Roman Catholic scholar, he
reconciles the political philosophy of Aristotle with
Christian faith.
 In doing so, he contends that a just ruler or
government must work for the "common good" of
all.
 Natural law in a finalistic-creationist context: the
order of the ends of nature coincides with the
sapiential plan that was God’s will at the moment of
Creation.
 Natural law = the cosmic order created by God;
eternal and unchangeable law; personal divine and
superior to man’s will, written in man’s heart.
 Practical reason can know natural law on the basis
of the observation of man’s natural preferences/
feelings/ likes:
 The conservation of life,
 Reproduction,
 Knowledge of the truth
 Living in a society
 The first and fundamental precept/ principle of
natural law is “good is to be done and pursued and
evil avoided”.
This precept is self-evident since all
creatures act on account of their end, which
is the good/true happiness for them
(eudaimonia).
Positive human law = particular provisions
deriving from natural law must also be
directed towards the common good.
Different interpretations of St Thomas
Aquinas’ reasoning:
 Law that fails to conform to natural (or
devine) law is not a law at all; an unjust
(unreasonable) law is not a law.
 Laws which conflict with natural law lose
their power of binding morally; it is an
abuse of authority; lacks/fails to moral
obligation.
 ‘Corruption of law’: there is justification in
disobeying a law which is unjust.
St Thomas Aquinas believed that an
informed conscience takes precedence over
(positive) law.
No individual should obey a law that he or
she believes to be unjust, because laws that
violate reason are not laws.
Moreover, laws must have sufficient flexibility
to be waived when necessary in the interests
of the common good).