For Spinoza, “all” that exists is the one Substance which he names as Nature or as God. Matter, extension, or the physical is but one of an infinity of expressions, or Attributes, of this Substance. Mind is another expression of this same Substance. Matter and Mind are the two Attributes to which we humans are privy in our perception of existence.
In Monist Pantheism, mind and matter are two ways of expressing the one Substance that is God or Nature (Deus sive natura). That one substance is not merely matter, it is not merely mind, it is both and infinitely more – thus it is a neutral monism (as opposed to a physical monism, physicalism; or to a mental monism, idealism, below). One can do no better than to read Spinoza directly to become acquainted with this primary form of Pantheism.
Idealism has two main varieties: Firstly, it is the philosophical doctrine that mentality, or mind, consciousness, experience, is the fundamental stuff or substance of reality. Secondly, Idealism is the view that the reality we perceive is merely an appearance or mask of an unknown reality.
“The universal mind is, respectively: (i) the essential quality of the theos in the word Pantheism, (ii) the mental quality of the universe itself, (iii) the mental quality that humans may attain—perhaps by drugs, as James and Watts stipulate, or by other means—that is temporarily numerically, thus qualitatively, identical to (ii), as it is a becoming one with the One, the fusing of the individual mind into the mind of God/Nature. This universal mind is not preferential or loving—for ‘God’ is not meant to be the personal monarch of the Abrahamic tradition, but rather ‘the God of the philosophers’, an abstract, permeating cosmic mind that cares not for earthly issues, let alone for those of a nation, people, or person.”
“‘Panentheism’ is supposed to mean ‘all in God’ (pan–en–theos), and thus God in all. But, in order to essentially distinguish it from Pantheism, Panentheism is the view that God is Nature and more.”
“Panentheism is then an incoherent idea for two main reasons, but ultimately it is coherent and distinctive for another reason: (i) In a strict sense Panentheism is an oxymoron because it proposes that God is existence and more than existence, implying the absurdity that there exists more than there exists. (ii) Panentheism can misconstrue Pantheism as Physicalist Pantheism (thus excluding a universal mind) and considers itself an advance upon that. But when we properly consider Pantheism in the Monist or Idealist forms, there proceeds no such advance. (iii) As actually distinct from Pantheism in the sense that God is ontologically distinct from the rest of Nature, Panentheism draws close to the notion of Classical Theism—however, Panentheism retains its distinctiveness from Pantheism and Classical Theism in that it proffers a non-providential God.”
It is as true to say that the World is immanent in God,
as that God is immanent in the World.
It is as true to say that God transcends the World, as that the World transcends God.
It is as true to say that God creates the World, as that the World creates God. (Pr, 348)
In all philosophic theory there is an ultimate which is actual in virtue of its accidents. It is only then capable of characterization through its accidental embodiments, and apart from these accidents is devoid of actuality. In the philosophy of organism this ultimate is termed ‘creativity’, and God is its primordial, non-temporal accident. In monistic philosophies, Spinoza’s or absolute idealism, this ultimate is God, who is also equivalently termed ‘The Absolute.’ In such monistic schemes, the ultimate is illegitimately allowed a final, ‘eminent’ reality, beyond that ascribed to any of its accidents. In this general position the philosophy of organism seems to approximate more to some strains of Indian, or Chinese, thought, than to western Asiatic, or European, thought. One side makes process ultimate; the other side makes fact ultimate. (PR, 7)
But ‘decision’ cannot be construed as a casual adjunct of an actual entity. It constitutes the very meaning of actuality. An actual entity arises from decisions for it, and by its very existence provides decisions for other actual entities which supersede it. (PR, 43)
Neither God, nor the World, reaches static completion. Both are in the grip of the ultimate metaphysical ground, the creative advance into novelty. Either of them, God and the World, is the instrument of novelty for the other. (PR, 349)
For the perfected actuality passes back into the temporal world, and qualifies this world so that each temporal actuality includes it as an immediate fact of relevant experience. For the kingdom of heaven is with us today. The action of the fourth phase is the love of God for the world. It is the particular providence for particular occasions. What is done in the world is transformed into a reality in heaven, and the reality in heaven passes back into the world. By reason of this reciprocal relation, the love in the world passes into the love in heaven, and floods back again into the world. In this sense, God is the great companion—the fellow-sufferer who understands. (PR, 390)
The history of theistic philosophy exhibits various stages of combination of these three diverse ways of entertaining the problem. There is, however, in the Galilean origin of Christianity yet another suggestion which does not fit very well with any of the three main strands of thought. It does not emphasize the ruling Caesar, or the ruthless moralist, or the unmoved mover. It dwells upon the tender elements in the world, which slowly and in quietness operate by love; and it finds purpose in the present immediacy of a kingdom not of this world. Love neither rules, nor is it unmoved; also it is a little oblivious as to morals. It does not look to the future; for it finds its own reward in the immediate present. (PR, 343)
The primordial appetitions which jointly constitute God’s purpose are seeking intensity, and not preservation. Because they are primordial, there is nothing to preserve. He, in his primordial nature, is unmoved by love for this particular, or that particular; for in this foundational process of creativity, there are no preconstituted particulars. In the foundations of his being, God is indifferent alike to preservation and to novelty. He cares not whether an immediate occasion be old or new, so far as concerns derivation from its ancestry. His aim16 for it is depth of satisfaction as an intermediate step towards the fulfilment of his own being. His tenderness is directed towards each actual occasion, as it arises. (PR, 105)