Guide Rationalism and Empiricism

The origin of concepts and the nature of knowledge
What is the basic or fundamental source of our knowledge? What provides the basic justification for our beliefs? How are we to provide a
systematic account of knowledge? The role of reason and experience. Rationalism and Empiricism.
Key concepts:
Knowledge and justification.
Foundationalism – the idea that a set of basic beliefs/concepts (accessed through reason or experience) provides a basis of infallible (cannot be
mistaken/false), incorrigible (cannot be changed) and indubitable (cannot be doubted) beliefs on which our other beliefs can be justified.
A priori and a posteriori knowledge.
Analytic and synthetic statements.
Necessary and contingent truths.
Key questions –
What is the origin of our concepts (general ideas we must employ to understand and categorise our experience of the world)?
What is the basis or source of our synthetic knowledge?
Overview in a nutshell
Rationalism holds that reason is the basic or prime source of knowledge. Concept innatism maintains that certain fundamental concepts are in
the mind from birth. They are ‘hard-wired’ into the mind. Candidates for such concepts include mathematical concepts, metaphysical ones such as
substance, causation and God, and moral ones of e.g. justice. Through our faculty of reason we are able to have synthetic a priori knowledge of
(the basic structure of) reality – what exists and what it’s like. This knowledge is of necessary truths. We can grasp (intuit) innate ideas (or, in the
Platonic view, the Forms) and understand their logical entailments and relations. In particular, our access to innate Ideas through reason and
capacity to employ logic allows us to know the essence of things.
Key examples - Plato’s account of the slave boy in the Meno; Descartes’ wax example (Meditation II), argument for innate idea of God
(Meditation III – Trademark Argument); knowledge of the external word (Meditation VI).
Worries. How plausible is an extreme rationalism? Surely we need some contact with the world through our senses to have knowledge. A less
extreme rationalism does not deny the senses a role, but reserves ‘top-grade’ knowledge for those things we know through the exercise of reason.
Cartesian approach to scientific enquiry – basic truths grounded in reason and these provide the basis for empirical investigation into the detailed
nature of the world. Leibniz – innate ideas as potentialities.
Empiricism is the claim that the basic source of knowledge is experience – we come to know of the world through our five senses – Locke, Hume
and Berkeley. Our concepts are ultimately derived from experience. Empiricism rejects concept innatism. We can combine, compare and abstract
from the raw material of sensory experience (impressions/sense-data) to form general ideas or concepts. At birth the mind is a tabula rasa. It has
the capacity to employ logical reasoning and to manipulate ideas, but it has no content. This is provided by experience.
Substantive or synthetic knowledge is a posteriori. Such knowledge is (according to the classical rationalism of e.g. Hume) of contingent truths.
Our a priori knowledge is restricted to analytic claims true in virtue of the meanings of the terms involved. It is here that we have knowledge of
necessary truths. However, they tell us nothing about the world, just the meaning of a concept.
Empiricism captures a common-sense intuition about how we come to have much of our knowledge, but maybe not convincing in explaining how
we come to know (non-trivial) a priori necessary truths. Also a rigorous empiricism may lead to scepticism – a challenge set out by Descartes in
his methodological use of doubt in Meditation I. Empiricism also faces the charge f incoherence or circularity in its account of the origin of
Key arguments for rationalism:
Plato – the role of the Forms. Meno – the slave boy.
Descartes – the role of doubt and the search for certainty. The wax example. Reason allows us to know the essence of things (inc. God) and that
the external world exists
Leibniz – allowing scope for experience – the block of marble analogy.
Some problems:
Platonic Forms are mysterious – what is the relationship of instantiation?
Reason is not infallible.
Without our senses we’d have nothing to think about.
Science tells us about the world and this requires empirical investigation.
There are no innate ideas.
Key arguments for empiricism:
Locke – the rejection of innate ideas. The picture of mind as a tabula rasa. The fundamental role of experience and the role of reason through
ideas of reflection.
Hume – Impressions and ideas. The copy principle. Hume’s Fork. Humean analysis of causation and induction. Hume and scepticism.
Some problems and questions:
Limitations on the senses – subjective, limited and fallible.
Sceptical worries – e.g. Locke and the veil of perception.
Experience cannot get us to necessary truths – and as Plato and Descartes show we do grasp necessary truths (e.g. the underlying nature of the
wax, mathematics, logic).
How can we explain our general ideas or concepts?