1. Michael Lacewing enquiries@alevelphilosophy.co.uk
Phenomenalism
Michael Lacewing
© Michael Lacewing

2. Mill’s ‘metaphysical’ phenomenalism
To establish what exists, we only have our sense experience to rely on
Physical objects are ‘permanent possibilities of sensation’

3. Mill’s ‘metaphysical’ phenomenalism
We think of particular possibilities of sensation as certain under particular circumstances.
This certainty is justified; it is based on our experience. When we experience particular sensations, we associate other possible sensations to them.
Physical objects just are these clusters of possible sensations.

4. Ayer’s ‘linguistic’ phenomenalism
Physical objects aren’t clusters of possible sensations. But talk of physical objects can be completely analysed as talk of sensations (only this analysis makes sense):
the symbol ‘table’ is definable in terms of certain symbols which stand for sense-contents, [though] not explicitly… sentences which contain the symbol ‘table’…can all be translated into sentences…which do not contain that symbol…, but do contain certain symbols which stand for sense-contents. (Language, Truth and Logic, p. 53)

5. Ayer’s ‘linguistic’ phenomenalism
Physical objects are ‘logical constructions’ out of sense data.
To say that a physical object exists is to say that certain sorts of sense data have been, are being, and would be experienced under certain conditions.

6. Objections
Phenomenalism can’t explain why we have consistent perceptions of physical objects.
Can we describe (and predict) the regularities in our sense data without referring to physical objects?
v. Ayer: The translation of a sentence about physical objects into sentences about possible sense data is virtually impossible, e.g. ‘there are penguins at the South Pole’.
v. Mill: what does it mean to talk of a cluster of possibilities existing?