PHYSICAL WORLD

Physical World

Physical world

Introduction

Most people idly wonder, at some point, whether the physical world exists, or whether it is all one great illusion. Descartes started his contention in the First Meditation by questioning or calling into question everything that he knew.

Locke made a famous distinction between 'primary' and 'secondary' qualities of objects. Primary qualities are the basic elements of modern physics: extension (shape), solidity and motion. Secondary qualities are things like colour, taste and smell, which are a major part of our perception of the world but can be understood in terms of the primary qualities that cause them. (Cahn, Eckert, 2005, pp 110) For instance, modern science tells us that colour can be understood by the propensity of a surface to reflect certain frequencies of light, dependent on its structure. So an orange doesn't really 'have' a colour, only the ability to cause the experience of orange in a mind.

Main Body

Descartes has said the senses (sentiens) are a part of the method of conceiving (cogitans), now he clarifies what he means when he talks of the senses in the remainder of the text. Properly talking, this is what in me is called 'sensing (sentire).' But this, accurately so taken, is not anything other than conceiving (cogitare).

If sensory insight and fantasy have been eradicated, the only likely interpretation is that his brain (men's) is to blame for his comprehending of wax in the diverse types it can take. So even though his senses have disclosed the wax to him in distinct types his brain has habitually, by methods unaligned of his senses, appreciated the essence of the wax and that it may be offered by the senses in differing ways.

So if we say that our experiences likely come at least in part from something external to us, where do ...