The truth is that there are two movements,—­a systole and diastole of the spiritual life,—­an expansion and a concentration.  The tendency has generally been to emphasise one at the expense of the other; but they must work together, for each is helpless without the other.  As Shakespeare says[46]—­

              “Nor doth the eye itself,
  That most pure spirit of sense, behold itself,
  Not going from itself, but eye to eye opposed,
  Salutes each other with each other’s form: 
  For speculation turns not to itself
  Till it hath travelled, and is mirrored there,
  Where it may see itself.”

Nature is dumb, and our own hearts are dumb, until they are allowed to speak to each other.  Then both will speak to us of God.

Speculative Mysticism has occupied itself largely with these two great subjects—­the immanence of God in nature, and the relation of human personality to Divine.  A few words must be said, before I conclude, on both these matters.

The Unity of all existence is a fundamental doctrine of Mysticism.  God is in all, and all is in God.  “His centre is everywhere, and His circumference nowhere,” as St. Bonaventura puts it.  It is often argued that this doctrine leads direct to Pantheism, and that speculative Mysticism is always and necessarily pantheistic.  This is, of course, a question of primary importance.  It is in the hope of dealing with it adequately that I have selected three writers who have been frequently called pantheists, for discussion in these Lectures.  I mean Dionysius the Areopagite, Scotus Erigena, and Eckhart.  But it would be impossible even to indicate my line of argument in the few minutes left me this morning.

The mystics are much inclined to adopt, in a modified form, the old notion of an anima mundi.  When Erigena says, “Be well assured that the Word—­the second Person of the Trinity—­is the Nature of all things,” he means that the Logos is a cosmic principle, the Personality of which the universe is the external expression or appearance.[47]

We are not now concerned with cosmological speculations, but the bearing of this theory on human personality is obvious.  If the Son of God is regarded as an all-embracing and all-pervading cosmic principle, the “mystic union” of the believer with Christ becomes something much closer than an ethical harmony of two mutually exclusive wills.  The question which exercises the mystics is not whether such a thing as fusion of personalities is possible, but whether, when the soul has attained union with its Lord, it is any longer conscious of a life distinct from that of the Word.  We shall find that some of the best mystics went astray on this point.  They teach a real substitution of the Divine for human nature, thus depersonalising man, and running into great danger of a perilous arrogance.  The mistake is a fatal one even from the speculative side, for it is only on the analogy of human personality that we can conceive of the perfect personality of God; and without personality the universe falls to pieces.  Personality is not only the strictest unity of which we have any experience; it is the fact which creates the postulate of unity on which all philosophy is based.