In all its forms, empiricism stresses the fundamental role of experience. As a doctrine in epistemology it holds that all knowledge is ultimately based on experience. Likewise an empirical theory of meaning or of thought holds that the meaning of words or our concepts are derivative from experience. This entry is restricted to epistemological empiricism. It is difficult to give an illuminating analysis of ‘experience’. Let us say that it includes any mode of consciousness in which something seems to be presented to the subject, as contrasted with the mental activity of thinking about things. Experience, so understood, has a variety of modes – sensory, aesthetic, moral, religious and so on – but empiricists usually concentrate on sense experience, the modes of consciousness that result from the stimulation of the five senses.
It is obvious that not all knowledge stems directly from experience. Hence empiricism always assumes a stratified form, in which the lowest level issues directly from experience, and higher levels are based on lower levels. It has most commonly been thought by empiricists that beliefs at the lowest level simply ‘read off’ what is presented in experience. If a tree is visually presented to me as green I simply ‘register’ this appearance in forming the belief that the tree is green. Most of our beliefs – general beliefs for example – do not have this status but, according to empiricism, are supported by other beliefs in ways that eventually trace back to experience. Thus the belief that maple trees are bare in winter is supported by particular perceptual beliefs to the effect that this maple tree is bare and it is winter.
Empiricism comes in many versions. A major difference concerns the base on which each rests. A public version takes beliefs about what we perceive in the physical environment to be directly supported by experience. A phenomenalist version supposes that only beliefs about one’s own sensory experience are directly supported, taking perceptual beliefs about the environment to get their support from the former sort of beliefs. The main difficulties for a global empiricism (all knowledge is based on experience) come from types of knowledge it is difficult to construe in this way, such as mathematical knowledge.
The role of meta-empirical theory assessment in the acceptance of atomism
