Before entering upon a consideration of the development of the theology of Islam, it will be well to mark clearly the three principles which run continuously through that development, which conditioned it for evil and for good and which are still working in it. In dealing with jurisprudence and with the theory of the state, we have already seen abundantly how false is the current idea that Islam has ceased to grow and has no hope of future development. The organism of Islam, like every other organism, has periods of rest when it appears to have reached a _cul de sac_ and to have outlived its life. But after these periods come others of renewed quickening and its vital energy pours itself forth again _alter et idem_. In the state, we saw how the old realms passed into decrepitude and decay, but new ones rose to take their places. The despotism by the grace of God of formal Islam was tempered by the sacred right of insurrection and revolution, and the People of Muhammad, in spite of kings and princes, asserted, from time to time, its unquenchable vitality. In theology the spirit breathes through single chosen men more than through the masses; and, in consequence, our treatment of it will take biographical form wherever our knowledge renders that possible. But whether we have men or naked movements, the begetters of which are names to us or less, three threads are woven distinctly through the web of Muslim religious thought. There is tradition (_naql_); there is reason (_aql_); and there is the unveiling of the mystic (_kashf_). They were in the tissue of Muhammad’s brain and they have been in his church since he died. Now one would be most prominent, now another, according to the thinker of the time; but all were present to some degree. Tradition in its strictest form lives now only with the Wahhabites and the Brotherhood of as-Sanusi; reason has become a scholastic handmaid of theology except among the modern Indian Mu‘tazilites, whom orthodox Islam would no more accept as Muslims than a Trinitarian of the Westminster confession would give the name of Christian to a Unitarian of the left wing; the inner light of the mystic has assumed many forms, running from plainest pantheism to mere devout ecstasy. But in the church of Muhammad they are all working still; and the catholicity of Islam, in spite of zealots, persecutions and counter-persecutions, has attained here, too, as in law, a liberty of variety in unity. Two of the principles we have met already in the students of _hadith_ and of speculative law. The Hanbalites maintained in theology their devotion to tradition; they fought for centuries all independent thinking which sought to rise above what the fathers had told; they fought even scholastic theology of the strictest type and would be content with nothing but the rehearsal of the old dogmas in the old forms; they fought, too, the mystical life in all its phases. On the other hand, Abu Hanifa was tinged with rationalism and