128 THE EARLIEST GREEK GEOMETRY. THALES
to him. But, lastly, the se-qet in No. 56 is -|f and, if se-qet
is taken in the sense of cot HFE, this gives for the angle
HFE the value of 54° 14'IS", which is 'precisely, to the
seconds, the slope of the lower half of the southern stone
pyramid of Dakshur; in Nos. 57-9 the se-qet, f, is the co
tangent of an angle of 53° 7' 48", which again is exactly the
slope of the second pyramid of Gizeh as measured by Flinders
Petrie; and the se-qet in No. 60, which is is the cotangent
of an angle of 75° 57'50", corresponding exactly to the slope
of the Mastaba-tombs of the Ancient Empire and of the
sides of the Medum pyramid. 1
These measurements of se-qet indicate at all events a rule-
of-thumb use of geometrical proportion, and connect themselves
naturally enough with the story of Thales’s method of measuring
the heights of pyramids.
The beginnings of Greek geometry.
At the beginning of the summary of Proclus we are told
that Thales (624-547 b. c.)
£ first went to Egypt and thence introduced this study
(geometry) into Greece. He discovered many propositions
himself, and instructed his successors in the principles under
lying many others, his method of attack being in some cases
more general (i. e. more theoretical or scientific), in others
more empirical (cdcrOrjTLKooTepov, more in the nature of simple
inspection or observation).’ 2
With Thales, therefore, geometry first becomes a deductive
science depending on general propositions; this agrees with
what Plutarch says of him as one of the Seven Wise Men:
‘ he was apparently the only one of these whose wisdom
stepped, in speculation, beyond the limits of practical utility:
the rest acquired the reputation of wisdom in politics.’ 3
(Not that Thales was inferior to the others in political
wisdom. Two stories illustrate the contrary. He tried to
save Ionia by urging the separate states to form a federation
1 Flinders Petrie, Pyramids and Temples of Gizeh, p. 162.
2 Proclus on Fuel. I, p. 65. 7-11.
3 Plutarch, Solon, c. 3.
