Pl. vires. (pl. vīrēs).]
1. Strength, force, energy, vigor.
c. 1630. T. Goodwin, Serm., Wks. 1681, I. III. 39. [Christ] Who then must be the immediate Uniter, by his own Vis or Power exerted in it.
1650. Hubbert, Pill Formality, 104. The Saints know this by experience, that there is a certain vis, a power infused into the soul from God, which was not before in them.
1788. Trifler, No. 17. 231. Charmed with the prospect which the vis of combined effects presented to him, he resolved to investigate the springs of action.
1882. Dr. J. Brown, John Leech, etc., 181. His verses … have more imaginative vis, more daintiness of phrase [etc.].
1888. Abp. Benson, in A. C. Benson, Life (1899), II. v. 200. There is no vis and there is also no learning, among them [sc. Reformers], out of Germany.
1907. P. T. Forsyth, Positive Preaching, v. 163. The great moral vis of the Reformation subsided into the renewed intellectualism of the seventeenth century dogmatists.
2. In special collocations with other Latin words.
In addition to those illustrated below, various others are or have been in use, as vis acceleratrix, centrifuga, centripeta, impressa, insita, etc. A number of these appear in dictionaries from about 1700 onwards.
a. Vis major, such a degree of superior force that no effective resistance can be made to it.
1601. Holland, Pliny, I. 599. Hailes, stormes of wind and raine, and such like impressions of the aire, which whensoever they doe light, are tearmed by the Lawyers, Vis major, i. the greater violence.
1866. Ld. Blackburn, in Hurlstone & Coltman, Rep., IV. 271. He can excuse himself by shewing that … the escape was the consequence of vis major or the act of God.
b. Vis inertiæ, the resistance naturally offered by matter to any force tending to alter its state in respect of rest or motion; also transf., tendency on the part of persons, etc., to remain inactive or unprogressive.
1906. [see INERTIA 1].
1710. J. Harris, Lex. Techn., II. s.v., This Vis Inertiæ is no where more conspicuous, than in the sudden Motion of a Vessel full of Liquor upon a Horizontal Plane.
1748. Hartley, Observ. Man, II. i. § 6. 31. Matter is a mere passive thing, of whose very essence it is, to be endued with a Vis inertiae.
1781. Phil. Trans., LXXI. I. 312. Not so much owing to the smallness of the quantity of powder that takes fire in that case as to the vis inertiæ of the generated fluid.
1836. I. Taylor, Phys. The. Another Life ii. 32. This power of the mind in overcoming the vis inertiæ of matter.
transf. 1755. Chesterf., Lett. to Bp. of Waterford, 26 June. Writing seems to be acting … which my vis inertiæ will not suffer me to undertake.
1780. H. Walpole, Lett. (1858), VII. 405. By the time absolute power is attained, it will … be charming in speculation, but prove to be nothing but the vis inertiæ.
1818. Edin. Rev., XXIX. 361. The vis inertiæ which strengthens the subject in repelling the aggressions of his rulers.
1878. Sir G. Scott, Lect. Med. Archit., vii. I. 272. There is a vis inertiæ in Art which is not easily overcome.
c. Vis viva, the operative force of a moving or acting body, reckoned as equal to the mass of the body multiplied by the square of its velocity.
1780. Encycl. Brit. (ed. 2), V. 3317/1. The vis viva, or absolute apparent strength of the stroke.
1808. Edin. Rev., XII. 122. The proposition on which the whole theory of the vis viva is actually founded.
1849. Sir W. Thomson, Math. & Phys. Papers (1882), I. 107. Notes on Hydrodynamics. On the Vis-viva of a liquid in motion.
1870. Lond., etc., Philos. Mag., Sept., 210. But a part only of the vires vivæ produced during the efflux has been transformed into heat.
1875. Croll, Climate & T., App. 546. The vis viva of vibration depends upon the force of the stroke.
d. Vis vitæ, vital force.
1752. Gentl. Mag., 67/1. All medicines whatever, which tend to lessen the vis vitæ, are pernicious.
a. 1817. T. Dwight, Trav. New Eng., etc. (1821), I. 385. A pungency, entirely peculiar, accompanied the smell; and appeared to lessen the vis vitae in a manner, different from any thing, which I had ever experienced before.
e. Vis a fronte, a force operating from in front (as in attraction or suction). Vis a tergo, a force operating from behind; a propulsive force.
1822. Good, Study Med., II. 15. Hence arose another hypothesis, which ascribed the propulsive power to a progressive vis à tergo. Ibid. (1825), (ed. 2), II. 18. The secernents or extreme arteries … operate by a kind of suction, which may be regarded as a vis à fronte.
1873. T. H. Green, Introd. Pathol. (ed. 2), 19. The combined effect of the diminished vis à tergo and of the arterial degeneration may, in some cases, be alone sufficient to cause arrest of the circulation.
