The Constitutional History of England by Henry Hallam, philosophical historian, 1777-1859.
[Refusing to negotiate is an aggressive act]
"With what justice those complaints were made, we are not now called upon to determine, since it cannot be pretended that the measures of France were of such a nature as to preclude the possibility of adjustment by negotiation; and it is impossible to deny, that the power which shuts up the channel of accommodation must be the real aggressor in war. To reject negotiation is to determine on hostilities; and, whatever may have been the nature of the points in question between us and France, we cannot but pronounce the refusal of such an authorised communication with that country, as might have amicably terminated the dispute, to be the true and immediate cause of the rupture which followed."
William Pitt, House of Commons, 1796