Locke’s cognitive model from An Essay Concerning Human Understanding (1690)

The foundation of Locke's cognitive model is his division of human thinking into a series of interrelated but distinct processes --each with its own parameters and functions. According to Locke, all thinking can be understood first to fall into one of the two

general categories of SENSATION or REFLECTION --Sensation describing the way in which "our senses, conversant bout particular sensible objects, do convey into the mind several distinct perceptions of things, according to those various ways wherein those objects do affect them" (122), and Reflection being "the perception of the operations of our own mind within us, as it is employed about the ideas it has got" (123). Believing that the mind is, at birth, an "empty cabinet" (48) or a sheet of "white paper, void of all characters, without any ideas" (121), he claims that these two modes of thinking,  sensations and Reflection, are "the only originals from whence all our ideas take their beginnings" (124). Reflection can not, however, occur except as there are thoughts present to reflect upon. Thus, for Locke, all thinking begins with Sensation --"The perception is the first operation of all our intellectual faculties, and the inlet of all our knowledge" (191).

Locke describes the process by which the senses furnish the mind with its first thoughts as a function of mediation. Walking a line between the skeptical and materialist dualist extremes, Locke claims that "the ideas of primary (material) qualities of bodies are resemblances of them, and their patterns do really exist in the bodies themselves, but the ideas produced in us by these secondary qualities have no resemblance of them at all" (173). The material world does, according to Locke exist, but we only have access through the mediation of certain secondary material qualities (such as motion, refraction, heat, etc.) and therefore have an 'idea' of its materiality but no real knowledge of it. It is these "ideas" which are, according to Locke, the fundamental building blocks of all human thought. Locke is, thus, strictly speaking neither a pure skeptic nor materialist, but advocates a postion which mediates between the two.

Having made the initial division of thinking into the two "operations" of Sensation and Reflection, and having described the way in which Sensation furnishes the mind with its primary material, Locke notes that while Sensation is at its root a passive process

(i.e., a sound wave hits the ear drum and produces an automatic response), Reflection can be active or passive and can actually intervene into the operation of Sensation (183, 186, 298). Having pointed this out, Locke goes on to examine and identify several sub-classes of thought which exist under the category of Reflection. This discussion takes the form, first, of a categorization of the types of ideas, the objects with which the reflection busies itself, which are present in the mind. According to Locke, all ideas fall into one of the two general categories of Simple or Complex--simple ideas being those ideas which are "not distinguishable into different ideas" (145), such as hot, cold, white, etc., and Complex ideas being those which are produced by the understanding "repeat[ing], compar[ing], and unit[ing]" (145) simple ideas. He further divides Complex ideas into the sub-categories of Modes, Substances, and Relations (215), defining Modes as what we today would think of as qualities, as power, identity, etc., Substances as things, such as the idea of a Man, and Relations in terms of mathematical relational properties such as squared, triangular, etc.

Locke also defines the many ways in which the mind goes about producing and   manipulating these ideas. Having already distinguished between Reflection and Sensation as two broad categories of thought, Locke defines several sub-categories of thought which fall under the category of Reflection, each with its own unique attribute. According to Locke, all Reflective thought falls into one of the following sub-categories: Memory (193) --the ability to recall an absent idea back into consciousness-- Retention (193) --the ability to hold a thought in the consciousness-- Discerning (202) --the ability to recognize the differences between things-- Comparing (204), the ability to recognize the similarities between things--Composition (205) --the ability to construct new ideas from the building blocks of other ideas-- and Abstraction (207) --the ability to discern abstract relational principles, such as mathematical proofs, which lie behind other ideas and therefore create an idea of the general. According to Locke, all human thought is explained by these divisions.

Another aspect of the human psyche with which Locke deals is that of the Will. Locke accounts for the existence of the human will by asserting that humans are basically hardwired to experience the sensations of pain and pleasure and that all action is the

result of a drawing towards the one or moving away from the other. He writes, "Pain has the same efficacy and use to set us on work that pleasure has, we being as ready to employ our faculties to avoid that, as to pursue this" (161). Later in the work, however, the creator mysteriously drops out of the picture and man becomes capable of choosing for himself what is pleasurable or painful (363), and only the hardwired mechanism which drives man towards pleasure and a way from pain remains a product of the Creator. Unfortunately, Locke never adequately describes where exactly the impetus to will such a

change originates.