An Essay Concerning Human Understanding

Understanding becomes clearer and deeper as ideas are considered relatively. The human brain often passively finds connections and disagreements between ideas; Locke refers to this as “intuitive knowledge” (523). An example is the comparison of a circle to a triangle. The mind does not have to actively consider the two shapes to recognize how they are different. Some relationships, which Locke refers to as “agreement and disagreement,” are not immediately apparent (524). An example of this would be the three angles of a triangle. The mind may find the relationship after observation during reflection and perception. When two ideas intersect and agree, they are considered “proofs.” The mind uses demonstrative rather than intuitive knowledge to find these relationships.

Locke begins this chapter by repeating certain philosophies that provide a base for discussing the extent of knowledge. Knowledge depends on ideas formed through sensory experience and reflection. Humans cannot use intuitive knowledge to consider the relationships among ideas. However, rational knowledge cannot reveal the entirety of an idea. Humans can understand the world only to the degree that they are willing to reflect on and find relationships among ideas. Locke proposes that human limitations will always hide certain relationships from consciousness. For example, the ideas of substances are extremely limited, and Locke suggests that humans are incapable of fully understanding the complexity of certain substances, such as gold. He describes the human mind as being in “the dark” in certain areas, including spirits and how substances interact.

In this chapter, Locke opens with an opposing argument. He suggests that the reader may be wondering how to determine between imagination/fantasy and concrete knowledge. Locke argues that simple ideas are easily identifiable as real. Complex ideas confirmed by other complex ideas are a testament to their reality. For this reason, moral ideas can be proven as easily and finally as mathematical equations. The reality of an idea requires that it conforms to its archetype. Humans have rational souls, designed by God, that adhere to the truth.

Locke argues that what defines truth is ideas that agree with one another and proposes two kinds of truth: “truth of thought and truth of words” (564). These two types of truth deal with either the moral or metaphysical. Humans can form true thoughts without assigning words, but language presents ideas with greater clarity and brings them closer to the truth. The mind can determine truth by examining the agreements and disagreements, as described in previous chapters. As ideas come together, they reveal truth. Words, however, are trickier, as they do not always represent the full capacity of an idea.

However, Locke argues that the pursuit of knowledge is not the most noble venture. After all, human minds are filled with incomplete knowledge and strange fancies. If ideas confirming other ideas defines truth, then those fancies may be taken as true.

Universal propositions attempt to outline general, truthful principles. Knowing, or certainty, depends on the agreement of ideas. Humans cannot be confident that any universal proposition is true without clearly defining the words it uses and the essences it describes. Locke proposes that because words are so slippery, we can never fully accept universal propositions. He refers once more to the example of gold. Because the concept of gold is nuanced and complex and because it conjures different images for different people, fully establishing universal propositions about it that all people accept is impossible. All individuals cannot accept that gold is not snow, for example, because they do not all understand the word with the same agreements and context. In addition, human senses limit their understanding; they cannot accept universal propositions that they have not yet experienced.

Maxims refer to self-evident propositions related to scientific inquiry. Locke questions whether people can immediately accept maxims without considering their agreements and disagreements. He argues that what humans perceive as self-evident is confirmed by other ideas and that maxims are limited in their usefulness when discussing knowledge. The mind accepts simple maxims based on how ideas agree with other ideas and require little effort of mind. An example of a maxim is that blue is not white. Although this concept seems innate, it is in fact a simple idea based on sensory input. Locke argues that maxims are rarely useful and can cloud judgment about words and ideas.

Universal propositions may be accepted as true, but, like maxims, they contribute little to the pursuit of human understanding. “Identical propositions” are statements that claim that something is itself; for example, “a soul is a soul” (598-99). This kind of statement, although true, is fruitless and does not advance knowledge. Another example of a universal proposition that Locke denounces is the use of an incomplete definition. For example, explaining the meaning of lead to someone by describing it as “a metal” may be true; however, it is inconsistent and incomplete. Locke argues that trifling propositions are verbally true but provide no instruction or new learning.

Humans gain knowledge of their own existence intuitively. Locke argues that human existence does not require evidence to be proven real. The very fact that humans can sense, perceive, and experience pleasure and pain indicates the reality of their existence.

Locke reiterates innate knowledge is nonexistent; therefore, God has not imparted innate knowledge upon humankind. However, the philosopher argues that God did impart the abilities to sense and perceive, which are foundational in recognizing God’s existence. Locke proposes that the conclusion of the existence of God follows a logical pattern of thought. First, a man recognizes his own existence. Second, he realizes that things cannot be created from nothing. Modes of thinking reveal that something or someone must be responsible for creation. Locke calls this the “certain and evident truth” that God exists (610). Humans can decipher knowledge about the spiritual world much the same way they can with the physical world.

Knowledge of the self comes through intuition, and knowledge of God comes through reason. The knowledge of others comes through sensation. Humans are aware of other people and animals only through sensory experience. Locke suggests that the evidence through the senses is too overwhelming to doubt. When people encounter other people, they cannot stop their minds from forming ideas. Locke proposes that those ideas produce either pleasure or pain.

Having denounced maxims, propositions, and principles, Locke sets forth a different pathway for improving knowledge. He argues that any headway in science has resulted from “clear, distinct, complete ideas” rather than the maxims they relied on (629). Preciseness, definition, and clarity lead to greater understanding. The danger of accepting propositions and maxims at face value is that humans can be misled by concepts that they can never consider certain. Locke believes that natural science will always be limited because humans can obtain only certain knowledge through sensory experience; because experience is limited, science is limited as well. This does not mean, however, that he does not view the pursuit of knowledge as unimportant. By finding agreements and clearly defining terms, scientists may get closer to certainty.

Locke proposes that knowledge is neither necessary nor voluntary. If it were, all humans would have all knowledge and would devote their lives to pursuing it. Instead, the pursuit of knowledge requires intention.

In addition to knowledge, God imparts the ability to judge so that humans can determine the right way to live. Judgment helps fill in the gaps that sensory experience leaves open. Knowledge represents a human’s ability to perceive, and judgment is the ability to find relationships and determine.

Although humans can never understand anything with certainty or create a clear picture of the truth, they must operate on certain probabilities. Locke proposes that probabilities form when humans confirm ideas through agreement and disagreement. Humans are dependent on probability. Because they cannot know anything with certainty, they must rely on probability to continue to move science and knowledge forward. Probability requires an idea to conform with other ideas and observations by multiple people.

Locke uses the word “assent” to mean the degree to which other people accept certain probabilities as true. Humans make errors when they hold tightly to previously conceived ideas that run counter to probabilities. Locke argues that those who cherish wrong ideas hold to them more tightly than those who accept right ones. Humans are more likely to assent if they see others assenting and if it aligns with their own experiences. In addition, they are faster to assent when multiple witnesses have attested to the idea. Testimonies, particularly of those with no investment in the probability, lend greater validity.

Sensation and reflection need reason for “the enlargement of our knowledge, and regulating our assent” (657). This means that reason is necessary to contribute to external and consensual knowledge. Locke proposes four degrees of reason. The first and greatest degree is the discovery of truth. The second is relating that truth to other ideas and finding their order. The third is understanding how ideas connect, and the fourth culminates in a conclusion based upon the first three. However, Locke cautions against conclusions, or syllogisms, because they are limiting. Syllogisms are useful for scholars only for the purpose of debate. Locke concludes by explaining that faith and reason are not mutually exclusive; instead, each advances the other.

Although faith and reason are not the same concepts, they complement one another. Reason seeks to establish certainty, while revelation establishes faith. Locke emphasizes once more that revelation is born from sensory experience and perception. Consequently, faith and reason function together. Faith requires reason to logically follow ideas about existence and creation. Reason requires faith to make sense of the unknown.

The search for truth requires intention. Locke suggests that humans must fall in love with the pursuit of knowledge. However, he warns against enthusiasm and the common trappings of philosophical minds. Locke suggests avoiding the imposition of one’s opinions or judgments on others. He argues that enthusiasm causes people to assent to ideas that lack logic and evidence. They believe things are true because they feel so strongly. Instead, the philosopher suggests that humans should trust God to direct them toward the truth.

Locke declares that error is not due to faulty knowledge. Instead, it implies a mistake in judgment. He argues that there are four types of error: “1. Want of proofs. 2. Want of ability to use them. 3. Want of will to see them. 4. Wrong measures of probability” (694). The philosopher suggests that humans will inevitably make errors in reasoning. This is part of the plight of the human condition. He attributes these errors to stubbornness or ignorance. However, Locke argues that humans make fewer errors in reasoning than many suppose. This is not because people have a greater understanding of the truth. Instead, Locke argues that humans have little interest in the truth or developing opinions.

Locke divides the realm of human understanding, called the sciences, into three categories. The first is the “nature of things,” which explores things and how they relate and function (707). The second is human purpose and the pursuit of happiness. The third is acquisition and communication of knowledge.