The term idealist is used in different ways. A person might be called an "idealist" if they desire or advocate a perfect or model outcome in various situations. For example, one might see a family of two parents, three children, a dog, nice home, and white picket fence as the "ideal" life. Or it might be "ideal" if Democrats and Republicans agreed on various political compromises. But in another sense, idealism refers to several philosophical systems of thought that understand reality itself as foundationally "mental," or that knowledge of anything is ultimately self-knowledge (e.g. knowledge of one's own mental states). In short, the philosophical idealist will generally hold that either everything is mind or all we can know is our own mind.
What is the definition of idealism?
To those unfamiliar with terms like "mind" being used in such a way, idealism can seem quite strange. And it is perhaps even more difficult to understand why this philosophy has any relevance whatsoever. But a basic sketch of idealism can help us see how it has permeated thought-culture and impacts our conversations about important topics, like belief in God and salvation.
The label "idealism" comes via reference to the first examples above, where we might understand an "ideal" state of affairs existing in one's own mind but perhaps not in the minds of others or physical reality. It is important to understand that idealism starts with subjective perception and mental states. That is, the beginning point for the idealist is his/her own perceptions and ideas of colors, shapes, sounds, and so forth. The idealist then reasons in various ways that mental existence of these things is the only possible affirmative reality of them; there is no way to rationally hold that the things of perception exist absent a mind. For the idealist, to deny the perception of colors and sounds is contradictory. And these perceptions and ideas cannot be physical in any way (all that is had is the idea of them). Thus, they (ideas) must exist in an immaterial way within a mind that understands and can reason through them. Since we can only prove/affirm what we can perceive, and we do not perceive any physical objects (only ideas), we have good reason to think that reality is comprised of mind (however this term might be ultimately reduced).
Eighteenth century philosopher and Anglican Bishop George Berkeley summarized a major idealist line of thinking with his notion of "esse est percipi" ("to be is to be perceived"). Berkeley essentially held that only ideas can be affirmed to exist, and that they continue existing when one is not thinking of them because God thinks of them. For Berkeley, all that we can justify is that we are spirits, and God, as spirit, sustains and gives ideas their existence. A much more influential later thinker, Immanuel Kant, introduced the enduring concept of "things to us" (phenomena) and "things in themselves" (noumena). Contrary to most interpretations of Berkeley, Kant does allow for the physical reality of things. But we can only understand these things through the latticework of our own minds. In many ways, idealist philosophy following Berkeley and Kant tends toward one or the other on its main points.
While not many have been compelled by Berkeley's brand of idealism, the influence of Immanuel Kant has been tremendous. Much of our contemporary dialogue on matters of God and salvation reduce to the notion of "true for me but not true for you" or "you cannot really know anything about what might exist 'out there,'" which renders agnosticism plausible. Some might claim these, and related claims, are an abuse of Kant's philosophy and idealism in general. But it is undeniable that Kant's epistemological idealism is correctly incorporated in the basic underwriting of these ideas. The prevalent notion of a person not being able to know things in themselves but only their own perceptions or ideas has become commonplace. This yields a false sense of reality as purely subjective. It emboldens people in their rationale for holding many bad ideas. Atheists and agnostics have employed the "mind/reality" bifurcation in denial of things like God's existence, that the Bible is special revelation from God, or that Jesus Christ died for sinners and rose from the tomb.
The philosophy of idealism finds no biblical compatibility. One clear point of demarcation begins in the first verse of the Bible, where God creates the heavens and the earth (Genesis 1:1). That there are existing, physical, mind-independent objects is obvious from the passage. Moreover, the remainder of Genesis chapter 1 teaches that physical things were made before any human existed to perceive them. The Bible is clear that Jesus Christ physically rose from the dead. That God created man with both material and immaterial aspects speaks to the relevance of both in the life of man now and in the everlasting state (Genesis 2:7; Revelation 21:1—22:5). The Bible also does not teach or imply any unreachable distance between the knowing subject and the object known. Quite the opposite. For example, Psalm 19 tells everyone that the "heavens declare the glory of God." It is not as if the glory of God is made clear to some and not others. Just because one person might be colorblind does not mean that there is no color. The star looks yellow to one person and white to another, but this does not mean there is no star observed and no discernable objective reality. Romans 1:18–20 tells us that God is known by all through His effects; by creation we know there is a divine Creator.
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