CHAPTER III

The Onlooker's Philosophic Malady

In his isolation as world spectator, the modern philosopher was bound
to reach two completely opposite views regarding the objective value of
human thought. One of these was given expression in Descartes' famous
words: Cogito ergo sum ('I think, therefore I am'). Descartes
(1596-1650), rightly described as the inaugurator of modern philosophy,
thus held the view that only in his own thought-activity does man find
a guarantee of his own existence.

In coming to this view, Descartes took as his starting-point his
experience that human consciousness contains only the thought pictures
evoked by sense-perception, and yet knows nothing of the how and why of
the things responsible for such impressions. He thus found himself
compelled, in the first place, to doubt whether any of these things had
any objective existence, at all. Hence, there remained over for him
only one indubitable item in the entire content of the universe - his
own thinking; for were he to doubt even this, he could do so only by
again making use of it. From the 'I doubt, therefore I am', he was led
in this way to the 'I think, therefore I am'.

The other conception of human thought reached by the
onlooker-consciousness was diametrically opposed to that of Descartes,
and entirely cancelled its conceptual significance. It was put forward
- not long afterwards - by Robert Hooke (1635-1703), the first
scientist to make systematic use of the newly invented microscope by
means of which he made the fundamental discovery of the cellular
structure of plant tissues. It was, indeed, on the strength of his