Swami Sivananda: “Semen or vital juice tones the nerves and brain and energises the system. He who has preserved his vital force by the vow of celibacy and sublimated it to Ojas-Sakti, can practise steady meditation for a long period. Only he can ascend the ladder of Yoga. Without Brahmacharya no iota of spiritual progress is possible. Brahmacharya is the very foundation on which the superstructure of meditation and Samadhi can be built up. Many people waste this vital energy—a great spiritual treasure indeed—when they become blind and lose their power of reason under excitement. Pitiable indeed is their lot! They cannotmake any substantial progress in Yoga.
(Source: pgs. 107-108, Concentration and Meditation)