The definition given by Corderius in his introduction to the mystical theology of Dionysius is modelled on the mysticism of John de la Cruz:—‘Theologia Mystica est sapientia experimentalis, Dei affectiva, divinitus infusa, quæ mentem ab omni inordinatione puram, per actus supernaturales fidei, spei, et charitatis, cum Deo intime conjungit.’—_Isagoge_, cap. ii. The most negative definition of all is that given by Pachymeres, the Greek paraphrast of Dionysius, who has evidently caught his master’s mantle, or cloak of darkness. ‘Mystical theology is not perception or discourse, not a movement of the mind, not an operation, not a habit, nothing that any other power we may possess will bring to us; but if, in absolute immobility of mind we are illumined concerning it, we shall know that it is beyond everything cognizable by the mind of man.’—_Dion. Opp._ vol. i. p. 722. In one place the explanations of Corderius give us to understand that the mysticism he extols does at least open a door to theosophy itself, _i.e._ to inspired science. He declares that the mystical theologian not only has revealed to him the hidden sense of Scripture, but that he can understand and pierce the mysteries of any natural science whatsoever, in a way quite different from that possible to other men—in short, by a kind of special revelation.—_Isagoge_, cap. iv. The reader will gather the most adequate notion of what is meant, or thought to be meant, by mystical theology from the description given by Ludovic Blosius, a high authority on matters mystical, in his _Institutio Spiritualis_. Corderius cites him at length, as ‘sublimissimus rerum mysticarum interpres.’ Happy, he exclaims, is that soul which steadfastly follows after purity of heart and holy introversion, renouncing utterly all private affection, all self-will, all self-interest. Such a soul deserves to approach nearer and ever nearer to God. Then at length, when its higher powers have been elevated, purified, and furnished forth by divine grace, it attains to unity and nudity of spirit—to a pure love above representation—to that simplicity of thought which is devoid of all thinkings. Now, therefore, since it hath become receptive of the surpassing and ineffable grace of God, it is led to that living fountain which flows from everlasting, and doth refresh the minds of the saints unto the full and in over-measure. Now do the powers of the soul shine as the stars, and she herself is fit to contemplate the abyss of Divinity with a serene, a simple, and a jubilant intuition, free from imagination and from the smallest admixture of the intellect. Accordingly, when she lovingly turns herself absolutely unto God, the incomprehensible light shines into her depths, and that radiance blinds the eye of reason and understanding. But the simple eye of the soul itself remains open—that is _thought_, pure, naked, uniform, and raised above the understanding.