|The gist of the first law of motion, namely that with no outside forces a body will never move, or if moving, will never stop.|
In c.300BC, Aristotle, supposedly, was one of the first to grapple with the outlines of the first law; discussions of which resulting from his investigations into the nature abhors a vacuum query, which he was an advocator of; Aristotle’s proto-version version of the first law was: 
“Nobody can give a reason why a body that has been put into motion in empty space should stop on its own account. Why should it stop in one place rather than in another? Thus it will remain at rest, or it will of necessity keep moving ad infinitum unless it is hindered from doing so.”
In 60AD, Hero stated the following on the matter: 
“Bodies will have a rapid motion through a vacuum where there is nothing to obstruct or repel them, until they are in contact.”
In 1490, Leonardo Da Vinci, in his notebooks, moved from simply describing inventions to a more intense search for underlying principles, the laws of motion, in particular; Da Vinci wrote: 
“Nothing whatever can be moved by itself, but its motion is effected through another. There is no other force.”
“All movement tends to maintenance, or rather that all moved bodies continue to move along as the impression of the force of their motors (original impulse) remains in them.”
In c.1600, Galileo Galilei outlined a proto-version of the first law of motion in the form of the principle of inertia, or Galileo's principle, refined, namely there are two states: being at rest and moving uniformly, which are to be treated as being the same. 
In 1687, Newton codified the first law of motion as follows:
“Every body perseveres in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by forces impressed.”
Social first law of motion
See main: Social first law of motionThe subject of the first law of motion applied socially, i.e. to human movement, seems to be quite involved, to say the least; the following three quotes, combined, seem to capture the gist of the application:
“Those which cannot act on any of our organs, either immediately and by themselves, or mediately, by the intervention of other bodies, exist not for us; since they can neither move us, nor consequently furnish us with ideas: they can neither be known to us, nor of course be judged of by us. To know an object, is to have felt it; to feel it, it is requisite to have been moved by it.”— Baron d’Holbach (1770), The System of Nature (pg. 16)
“The only thing which can be directly perceived by the senses is force, to which may be reduced light, heat, electricity, sound and all the other things which can be perceived by the senses.”— James Maxwell (1847), age 16 answer to homework exercise for Scottish philosopher William Hamilton (1788-1856) on the properties of matter 
“Every force tends to give motion to the body on which it acts; but it may be prevented from doing so by other opposing forces, so that equilibrium results, and the body remains at rest. In this case the force performs no work. But as soon as the body moves under the influence of the force, work is performed.”— Rudolf Clausius (1875), “Mathematical Introduction”
1. Genz, Henning. (1994). Nothingness: the Science of Empty Space (pgs. 73, 108). Perseus Publishing.
2. Shlain, Leonard. (2009). Leonardo’s Brain: Understanding da Vinci’s Creative Genius (manuscripts, pg. 6; spurge, pg. 9; Machiavelli, pg. 27; desire to know, pg. 75; laws of motion, pgs. 111-14). Lyons Press, 2014.
3. Gleick, James. (2003). Isaac Newton (pgs. 129-30). Vintage Books.
● Newton’s first law (section) – Wikipedia.