The point of the wedge is quite indefinite, the extremely diffuse light gradually fading into invisibility at a height which may range from 50° to 70° or even more, according to the keenness of the observer's vision.
On the other hand, they are constantly impressed by his power of reasoning both deductively and inductively, by the subtlety and fertility of invention with which he applies analogies, by the clearness and keenness of his observation, by the fulness of matter with which his mind is stored, and by the consecutive force, the precision and distinctness of his style, when employed in the processes of scientific exposition.
Hence the aim of education was to make young people thoroughly " Greek," to fill them with the " Greek " spirit, with courage and keenness in the quest of truth, and with a devotion to all that was beautiful.
But Lynceus, whose keenness of sight was proverbial, saw Castor through the trunk and warned his brother, who thereupon slew the mortal Castor; finally, Pollux slew Lynceus, and Idas was struck by lightning (Apollodorus iii.
While in public life Conkling always attracted attention by his abilities, his keenness and eloquence in debate, his aggressive leadership and his striking personality.
But he writes with keenness and wit, and knows well how to use the materials already often taken advantage of by earlier deists.
The point in dispute has not in his hands the all-absorbing importance it afterwards attained, and the keenness of later distinctions is as yet unknown.
Under such conditions the deeply-rooted nature of the blood-sucking instinct is most remarkable; for insects whose ancestors for many generations may not have tasted blood will seek for it with the utmost keenness and pertinacity so soon as an opportunity presents itself.
(I) Tertullian was a man of great originality and genius, characterized by the deepest pathos, the liveliest fancy, and the most penetrating keenness, and was endowed with ability to appropriate and make use of all the methods of observation and speculation, and with the readiest wit.
The notes of this journey are written in a light and amusing style, showing Hume's usual keenness of sight in some directions and his almost equal blindness in others.
Each year the number of anti-slavery petitions received and presented by him increased; perhaps the climax was in 1837, when Adams presented a petition from twenty-two slaves, and, when threatened by his opponents with censure, defended himself with remarkable keenness and ability.
The keenness of the conflict as it approached the crisis of 1843 checked the liberality of the people for this object, but by 1841 £305,747 had been collected and 222 churches built.
The keenness of the satire on courts, parties and statesmen certainly suggests that it was planned while Swift's disappointments as a public man were still rankling and recent.
In the extent of his knowledge, in keenness of observation, in variety of style, in his literary output, he has been compared to Voltaire; but it is perhaps as the forerunner of the great Renaissance Platonists that he will be chiefly remembered.
He continued to take part in the proceedings of various learned societies; and only a few months before his death, at the Leicester meeting of the British Association, he attested the keenness with which he followed the current developments of scientific speculation by delivering a long and searching address on the electronic theory of matter.
Nowhere, however, were the keenness and clearness of his intellect more conspicuous than in this brilliant effort, which, if it failed in its immediate object, was highly effective in secondary results.