Empiricism and Rationalism - TCE Philosophy (Tasmania)
“Sources of knowledge: empiricism and rationalism”
Empiricism and rationalism are rival theories about where knowledge comes from. Empiricists such as Locke and Hume say all our concepts and substantive knowledge trace back to sense experience, so the mind begins as a blank slate. Rationalists such as Descartes and Plato say reason, not the senses, is the foundation of certain knowledge, and that some ideas or truths are known independently of experience. You are asked to explain both schools, present their key arguments, and evaluate which better explains how we know things.
What this dot point is asking
This dot point belongs to Unit 1 of the TASC Philosophy course, where epistemology is introduced as the study of the nature and sources of knowledge. Having met the definition of knowledge as justified true belief, you now examine the deeper question of where justification ultimately comes from: the world delivered through the senses, or the mind reasoning on its own.
The empiricist tradition
Empiricism holds that experience derived from the senses is the source of all knowledge. John Locke argued that the mind at birth is a tabula rasa, a blank tablet, with no innate ideas printed on it. Everything we can think about arrives either through sensation, our outer experience of the world, or reflection, our inner experience of our own mental operations. Complex ideas are built from simple ideas that ultimately came from experience. David Hume sharpened this into a tool of criticism: every genuine idea must be traceable to a prior impression, a vivid sensory experience. If a supposed idea cannot be traced to any impression, Hume treats it as empty.
The theory that all knowledge, or at least all substantive knowledge of the world, is grounded in and derived from sense experience. There are no innate ideas; the mind acquires its content through sensation and reflection.
The rationalist tradition
Rationalism holds that reason rather than experience is the foundation of certainty in knowledge. Rene Descartes sought a truth so secure that no doubt could touch it, and found it not in the senses, which can deceive, but in pure thought: the cogito, his certainty that he exists as a thinking thing. Descartes held that some ideas are innate, placed in the mind independently of experience, including the idea of God and the basic truths of mathematics. Plato earlier argued in the Meno that an untaught slave boy can be led to geometrical truths by questioning alone, which Plato explained as recollection of knowledge the soul already possessed. For rationalists the senses give at best unreliable opinion, while reason grasps necessary, universal truths.
Both camps want knowledge; they disagree about its origin. Rationalists prize a priori knowledge, known through reason independently of experience, such as mathematics. Empiricists insist even our most abstract concepts were assembled from sensory raw material.
The case each side makes
The empiricist points to the obvious dependence of thought on experience. A person born without sight has no genuine idea of colour, which suggests concepts really do come from the senses. Hume used his impression test to challenge metaphysical notions like necessary causal connection, arguing we never actually observe a power making one event produce another, only constant conjunction. The rationalist replies that experience alone cannot deliver the necessity and universality found in mathematics: no number of observed triangles proves that all triangles must have angles summing to two right angles. Such truths seem known by reason. Rationalists also argue that learning requires some prior structure in the mind, since a truly blank slate could not organise sensory chaos into experience at all.
Take the belief that 7 plus 5 equals 12. Empiricist analysis: the concepts of number came from counting objects in experience, though the relation is then seen by thought. Rationalist analysis: the truth is necessary and could not be otherwise, so it is known a priori by reason, not established by any particular act of counting. Asking how a belief is justified, by experience or by reason, locates the debate.
Toward a synthesis
The sharp opposition softened over time. Immanuel Kant argued that both sides were partly right: knowledge requires sensory input, but the mind actively structures that input using categories it supplies itself, so that, in his famous slogan, thoughts without content are empty while intuitions without concepts are blind. This suggests knowledge is a joint product of experience and reason rather than the work of either alone. For the TASC course you should be able to present the strongest version of each school, deploy a signature argument such as Hume's impression test or Plato's slave boy, and reach a reasoned judgement about how much of knowledge each can explain.
Rationalists do not deny that we have experiences or use them. They deny that experience is the foundation of certain knowledge, holding that reason supplies truths and ideas experience cannot. Saying rationalists ignore the senses misrepresents Descartes, who studied the physical world closely. The claim is about ultimate justification, not whether we observe anything.
Exam-style questions
Questions in the style of TASC exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
Practice6 marksExplain the difference between empiricism and rationalism about the source of knowledge, using one philosopher from each tradition.Show worked answer →
A 6 mark response needs both positions, named defenders, and a clear contrast.
Empiricism. All substantive knowledge derives from sense experience; the mind has no innate ideas. John Locke holds the mind begins as a tabula rasa and acquires ideas through sensation and reflection. David Hume sharpens this with the impression test: every genuine idea must trace back to a prior sensory impression.
Rationalism. Reason, not the senses, is the foundation of certain knowledge, and some ideas or truths are known a priori. Rene Descartes treats the cogito and mathematical truths as known by reason and holds that some ideas are innate.
Contrast. Markers reward a sharp statement that the dispute is about the source of knowledge: empiricists ground it in experience, rationalists in reason. Naming a signature argument from each side (Locke's blank slate or Descartes' innate ideas) secures full marks.
Practice16 marks"All our knowledge ultimately comes from experience." Critically evaluate this empiricist claim, referring to both empiricism and rationalism.Show worked answer →
A 16 mark extended argument essay should advance and defend a thesis.
Exposition. State the empiricist claim and its leading defenders (Locke, Hume), then the rationalist alternative (Descartes, Plato's slave boy in the Meno), which holds that some truths are known a priori by reason.
Case for the claim. Concepts seem to depend on experience: a person blind from birth has no genuine idea of colour, supporting Locke's blank slate and Hume's impression test.
Objection. Rationalists argue experience cannot deliver the necessity and universality of mathematics: no number of observed triangles proves all triangles must have angles summing to two right angles. They also argue a wholly blank slate could not organise sensory chaos into experience at all.
Synthesis and judgement. Kant argued both sides are partly right: knowledge requires sensory input but the mind structures it with its own categories, so thoughts without content are empty and intuitions without concepts blind. Conclude with a defended position, for example that experience supplies the content of empirical knowledge while reason supplies its necessary structure, so the strong empiricist claim is too simple. Markers reward a clear thesis, accurate signature arguments from each side, the Kantian synthesis, and a reasoned conclusion.