No less interesting than instructive and conclusive, is reference of this question to those intellectual principles which give birth to the game of Chess, per se, viz.:
As a primary fundamental, with the power to give check, is associated concurrently the obligation upon the King thus checked, not to remain in check.
Secondly: The totality of powers assigned to the Chess-pieces is the ability to move, provided the King be free from check. This totality of powers may be denoted by the indefinite symbol, X.
The play thus has for its object:
The reduction to zero of the adverse X, by the operation of the kindred X.
This result is checkmate in its generalized form. In effect, it is the destruction of the power of the adverse pieces to move, by means of check made permanent.
By the law of continuity it is self-evident that:
The power to move appertaining either to White or to Black, runs from full power to move any piece (a power due to freedom from check), down to total inability to move any piece, due to his King being permanently checked, i.e., checkmated.
This series cannot be interrupted without obvious violation of the ethics of the game; because, so long as any part of X remains, the principle from which the series emanated still operates, and this without regard to quantity of X remaining unexpended.
Thus, a game of Chess is a procedure from total ability to total disability; i.e., from one logical whole to another; otherwise, from X to zero.