Philosophical influences

Till the middle of the 19th C, psychology was a mainly speculative discipline involving metaphysical debates on the nature of mind. Kant's scepticism about the possibility of a science of psychology discouraged empirical investigation. Around the mid 19th C. however several currents of thought in philosophy and science contributed to the development of experimental psychology.

• In Philosophy - Critical empiricism (eg. Popper), Positivism, Associationism

• In Science - Physiology, Theory of Evolution, Atomism, Quantification, Statistics

In the 20th century the major influence came from Logical positivism:

• Rejection of metaphysics (statements are meaningful only if they are verifiable)

• Only two sources of knowledge - logical reasoning (analytic a priori) and empirical experience (synthetic a posteriori)

• Correspondence rules link theoretical to observational terms (analytic)

• Theoretical axioms express observational portion of theory (synthetic)