Sri Aurobindo
Letters of Sri Aurobindo
Volume IV - Part 3
You mean the doctors1. But even all doctors do not agree on that; there are many (I have read their opinions) who say that sex-satisfaction is not an absolute necessity and sex-abstinence can be physically very beneficial and is so – of course under proper conditions. As for scientists the product of the sex glands is considered by them (at least so I have read) as a great support and feeder of the general energies. It has even been considered that sex force has a great part to play in the production of poetry, art etc. and in the action of genius generally. Finally, it is a doctor who has discovered that the sex-fluid consists of two parts, one meant for sex-purposes, the other as a basis of general energy, 
and if the sex-action is not indulged, the first element tends to be turned into the second (retas into ojas, as the Yogis had already discovered). Theories? So are the statements or inferences of the opposite side – one theory is as good as another. Anyhow I don’t think that the atrophy of the sex-glands by abstinence can be supported by general experience. X’s contention [that the sex-glands of those who practise Brahmacharya may atrophy] is however logical if we take not individual results but the course of evolution and suppose that this evolution will follow the line of the old one, for the useless organs are supposed to disappear or deteriorate. But will the supramental evolution follow the same course as the old one or develop new adaptations of its own making? – that is the uncertain element.