Table of Contents
- Revolt Against Idealism
- Turn from Rationalism to Empiricism
- Turn from Extreme Metaphysics to Common Sense
- Turn from Skepticism to Common Sense
- Turn from Obscurity to Clarity and Precision
Revolt Against Idealism
- Contemporary Analytic Philosophy began with the Revolt against Idealism, led by Bertrand Russell and G.E. Moore at the turn of the 20th century.
- The British idealist F.H. Bradley had held that:
- The Absolute is the single indivisible whole of experience. Only the Absolute is real.
- Time, space, change, and other categories of thought are self-contradictory and therefore not real.
- The revolt against Idealism consisted of:
- A turn from Rationalism to Empiricism
- A turn from Extreme Metaphysics to Common Sense
- A turn from Skepticism to Common Sense
- A turn from obscurity to clarity and precision.


Turn from Rationalism to Empiricism
- Following Hume, Contemporary Analytic Philosophy rejected Rationalism, the view that some contingent truths can be known a priori. Philosophers no longer thought, as Kant did, that laws of nature could be proved independently of experience.
- Britannica Article on Analytic Philosophy
- “Accordingly, many empiricists insist on a sharp dichotomy between the physical sciences, which ultimately must verify their theories by observation, and the deductive or a priori sciences—e.g., mathematics and logic—the method of which is the deduction of theorems from axioms. The deductive sciences, in the empiricists’ view, cannot produce justified beliefs, much less knowledge, about the world.”
Turn from Extreme Metaphysics to Common Sense
- Philosophers once said things like: time is unreal, tomatoes aren’t red or any other color, physical objects don’t exist.
- Contemporary Analytic Philosophers reject such claims by appealing to Common Sense.
- In Some Judgments of Perception (1918) G.E. Moore argued:
- “This, after all, you know, really is a finger: there is no doubt about it: I know it, and you all know it. And I think we may safely challenge any philosopher to bring forward any argument in favor either of the proposition that we do not know it, or of the proposition that it is not true, which does not at some point, rest upon some premise which is, beyond comparison, less certain than is the proposition which it is designed to attack.”
- Thus, for example, Moore would argue that it’s more certain that tomatoes are red than that Locke’s and Berkeley’s arguments against secondary qualities are sound.
Turn from Skepticism to Common Sense
- Hume argued that there’s no rational foundation for believing the common-sense worldview of physical objects.
- “It is a question of fact, whether the perceptions of the senses be produced by external objects, resembling them: how shall this question be determined? By experience surely; as all other questions of a like nature. But here experience is, and must be entirely silent. The mind has never anything present to it but the perceptions, and cannot possibly reach any experience of their connexion with objects. The supposition of such a connexion is, therefore, without any foundation in reasoning.”
- Contemporary philosophers “refute” Hume’s argument by pointing out that the common-sense standard of rationality governing actual belief is effectual, able to change belief. During deliberation, for example, jurors may change their minds because of rational argument. But skeptical arguments about the physical world have no effect on belief. As Hume concedes, “Nature is too strong for principle.”
Turn from Obscurity to Clarity and Precision
Mathematics became rigorous in the 19 century, for example, by replacing the incoherent notion of an infinitely small number with the concept of limit. After regressing, philosophy became more rigorous in the 20 century, adopting higher standards of clarity and precision.
Three Examples
Symbolic Logic
- The argument-form Hypothetical Syllogism was long considered valid:
- A→B
- B→C
- So A→C
- But contemporary logicians have discovered a flaw in the inference:
- Let
- A = I win the lottery
- B = I give half my annual income to charity
- C = I will not have enough to live on.
- The premises of this argument are true but the conclusion false:
- If I win the lottery, I will give half my annual income to charity.
- If I give half my annual income to charity, I will not have enough to live on.
- Therefore, if I win the lottery, I will not have enough to live on.
- Logicians thus use a modified form of Hypothetical Syllogism:
- A→B
- (A&B)→C
- So A→C
- The counterexample fails because the second premise is false:
- If I win the lottery, I will give half my annual income to charity.
- If I win the lottery and give half my annual income to charity, I will not have enough to live on.
- Therefore, if I win the lottery, I will not have enough to live on.
- Let
Critique of Berkeley’s Species Argument
- Berkeley’s Argument
- If tomatoes had a particular color they would appear that color to different species.
- Tomatoes appear red to humans but yellowish-brown to dogs.
- Therefore tomatoes aren’t any particular color, including red.
- Analysis
- The argument fails because the first premise is false.
- To say an object is red (for humans) is to say it would appear red to humans with normal vision under normal perceptual conditions. In general, to say an object is red for a species is to say that it would appear red to members of that species with normal vision under normal conditions.
- Color is thus species-relative. Tomatoes are red relative to humans and yellowish-brown relative to dogs.
- Galileo, Locke, Berkeley, and Hume were right to distinguish primary qualities (mass, shape, volume) and secondary qualities (color, smell, taste, sound). But they got the distinction wrong. It’s false that secondary qualities exist only in the mind. Rather, secondary qualities are relations between objects and species with sensory organs.
Free Will
- A classic philosophic problem is whether human beings have free will. The answer depends in large part on the meaning of free will.
- Two proposals:
- Free will is the ability to choose among options.
- Free will is the ability to do otherwise.
- The first proposal is wrong.
- A chess-playing computer such as IBM’s Big Blue chooses among options, i.e. its possible moves. Big Blue thus able to choose among options, since it in fact does. But it’s absurd to think that an electronic device executing the line-by-line instructions of a computer program acts of its own free will.