Thirdly, Leibniz, in a dialogue[61] written on his journey of 1676 to visit Spinoza, raised the question whether the moment at which a man dies may be regarded as both the last moment at which he is alive and the first at which he is dead, as it must be by Aristotle's theory of continuity. Agreement with this view violates the law of contradiction; denial of it implies that two moments can be immediately adjacent. By the denial, then, we are led to regard space and time as made up of indivisible points and moments, and thus, since we can draw one and only one parallel from any point in the diagonal of a square to a given side, the diagonal will contain the same (infinite) number of points as that side, and will therefore be equal to it. In this Leibniz repeated an argument used by the ancient Arabs, Roger Bacon, and William of Occam. This Leibniz considered to be a proof that a line cannot be an aggregate of points. Indeed, their number would be "the number of all numbers" of the greatest possible integer, which _is_ not. It does not seem, further, that any light is thrown on the logical question of human mortality or immortality by legal decisions. It would appear that one can, legally speaking, be alive for any period less than twenty-four hours after one is dead and be dead for any period less than twenty-four hours before one's death. At least, according to _Salkeld_, i. 44, it was "adjudged that if one be born the first of February at eleven at night, and the last of January in the twenty-first year of his age, at one of the clock in the morning, he makes his will of lands, and dies, it is a good will, for he was then of age." In Sir Robert Howard's case (_ibid._, ii. 625) it was held by Chief Justice Holt that "if A be born on the third day of September; and on the second day of September twenty-one years afterwards he make his will, this is a good will; for the law will make no fraction of a day, and by consequence he was of age." But it is hardly necessary to remark that in this way the problem with which we are concerned is merely shifted and not solved. For the question as to whether there is or is not a last moment of a man's life is not answered by the decision that he dies legally twenty-four hours before or after he dies in the usual sense of the word, and the problem arises as to whether there is or is not a last moment of his legal age.[62]