With regard to what I have just called the two great methods in Yoga, we find that by one of these a man treads the path of knowledge by Buddhi–the pure reason; and the other the same path by Manas–the concrete mind. You may remember that in speaking yesterday of the sub- divisions of Antah-karana, I pointed out to you that there we had a process of reflection of one quality in another; and within the limits of the cognitional aspect of the Self, you find Buddhi, cognition reflected in cognition; and Ahamkara, cognition reflected in will; and Manas, cognition reflected in activity.
Bearing those three sub-divisions in mind, you will very readily be able to see that these two methods of Yoga fall naturally under two of these heads. But what of the third? What of the will, of which Ahamkara is the representative in cognition? That certainly has its road, but it can scarcely be said to be a “method”. Will breaks its way upwards by sheer unflinching determination, keeping its eyes fixed on the end, and using either buddhi or manes indifferently as a means to that end. Metaphysics is used to realise the Self; science is used to understand the Not-Self; but either is grasped, either is thrown aside, as it serves, or fails to serve, the needs of the moment.
Often the man, in whom will is predominant, does not know how he gains the object he is aiming at; it comes to his hands, but the “how” is obscure to him; he willed to have it, and nature gives it to him. This is also seen in Yoga in the man of Ahamkara, the sub-type of will in cognition. Just as in the man of Ahamkara, Buddhi and Manas are subordinate, so in the man of Buddhi, Ahamkara and Manas are not absent, but are subordinate; and in the man of Manas, Ahamkara and Buddhi are present, but play a subsidiary part. Both the metaphysician and the scientist must be supported by Ahamkara.
That Self-determining faculty, that deliberate setting of oneself to a chosen end, that is necessary in all forms of Yoga. Whether a Yogi is going to follow the purely cognitional way of Buddhi, or whether he is going to follow the more active path of Manas, in both cases he needs the self-determining will in order to sustain him in his arduous task. You remember it is written in the Upanishad that the weak man cannot reach the Self. Strength is wanted. Determination is wanted. Perseverance is wanted. And you must have, in every successful Yogi, that intense determination which is the very essence of individuality.
Now what are these two great methods? One of them may be described as seeking the Self by the Self; the other may be described as seeking the Self by the Not-Self; and if you will think of them in that fashion, I think you will find the idea illuminative. Those who seek the Self by the Self, seek him through the faculty of Buddhi; they turn ever inwards, and turn away from the outer world. Those who seek the Self by the Not-Self, seek him through the active working Manas; they are outward-turned, and by study of the Not-Self, they learn to realise the Self. The one is the path of the metaphysician; the other is the path of the scientist.