This is the Deity, or the Mind that presides in the Universe.
Chapter IX., at great length, discusses the first part of the subject--the framing of primary ideas regarding the Divine Nature.

He proves the existence of an original mind from design, &c., in the world; he then finds this mind to be benevolent, on occasion of which he has to deal with the great question of Evil, giving reasons for its existence, discovering its uses, narrowing its range as compared with good, and finally reducing it by the consideration and proof of immortality; he ends by setting forth the other attributes of God--providence, holiness, justice, &c.
In Chapter X., he considers the Affections, Duty, and Worship to be exercised towards God.

The moral sense quite specially enjoins worship of the Deity, internal and external; internal by love and trust and gratitude, &c., external by prayer, praise, &c.

[He seems to ascribe to prayer nothing beyond a subjective efficacy.] In the acknowledgment of God is highest happiness, and the highest exercise of the moral faculty.
In Chapter XI., he closes the whole book with remarks on the Supreme Happiness of our Nature, which he makes to consist in the perfect exercise of the nobler virtues, especially love and resignation to God, and of all the inferior virtues consistent with the superior; also in external prosperity, so far as virtue allows.

The moral sense, and the truest regard for our own interest, thus recommend the same course as the calm, generous determination; and this makes up the supreme cardinal virtue of Justice, which includes even our duties to God.
Temperance in regard to sensual enjoyments, Fortitude as against evils, and Prudence, or Consideration, in regard to everything that solicits our desires, are the other virtues; all subservient to Justice.