Ética, Parte III, Definición de los afectos 6

This definition explains sufficiently clearly the essence of love; the definition given by those authors who say that love is the lover's wish to unite himself to the loved object expresses a property, but not the essence of love; and, as such authors have not sufficiently discerned love's essence, they have been unable to acquire a true conception of its properties, accordingly their definition is on all hands admitted to be very obscure. It must, however, be noted, that when I say that it is a property of love, that the lover should wish to unite himself to the beloved object, I do not here mean by wish consent, or conclusion, or a free decision of the mind (for I have shown such, in II. xlviii., to be fictitious); neither do I mean a desire of being united to the loved object when it is absent, or of continuing in its presence when it is at hand; for love can be conceived without either of these desires; but by wish I mean the contentment, which is in the lover, on account of the presence of the beloved object, whereby the pleasure of the lover is strengthened, or at least maintained.