Law of thought

Were as laws of thought in the history of philosophy and philosophical logic, especially in the psychologism of the 19th century, called logical rules, laws or principles, insofar as it - this was the psychologistic view - were regarded as natural laws of thought.

On the relationship between psychology and logic Gottlob Frege has noted:

In particular, different sets of identity, the law of contradiction, the law of excluded middle and the principle of sufficient reason were grouped together with the names of the laws of thought and logical principles. These rates, which are present in different formulations were considered in the tradition partly as the logical, partly as a metaphysical and partly as an epistemological principles and have also been denied as such both represented as.