The Uncertainty of Causation
Hume observes that while we may perceive two events that
seem to occur in conjunction, there is no way for us to know the
nature of their connection. Based on this observation, Hume argues
against the very concept of causation, or cause and effect. We often
assume that one thing causes another, but it is just as possible
that one thing does not cause the other. Hume claims
that causation is a habit of association, a belief that is unfounded
and meaningless. Still, he notes that when we repeatedly observe
one event following another, our assumption that we are witnessing
cause and effect seems logical to us. Hume holds that we have an
instinctive belief in causality, rooted in our own biological habits,
and that we can neither prove nor discount this belief. However,
if we accept our limitations, we can still function without abandoning
our assumptions about cause and effect. Religion suggests that the
world operates on cause and effect and that there must therefore
be a First Cause, namely God. In Hume’s worldview, causation is
assumed but ultimately unknowable. We do not know there
is a First Cause, or a place for God.
The Problem of Induction
Induction is the practice of drawing general conclusions
based on particular experiences. Although this method is essential
to empiricism and the scientific method, there is always something
inherently uncertain about it, because we may acquire new data that
are different and that disprove our previous conclusions. Essentially,
the principle of induction teaches us that we can predict the future based
on what has happened in the past, which we cannot. Hume argues that
in the absence of real knowledge of the nature of the connection
between events, we cannot adequately justify inductive assumptions.
Hume suggests two possible justifications and rejects them both.
The first justification is functional: It is only logical that the
future must resemble the past. Hume pointed out that we can just
as easily imagine a world of chaos, so logic cannot guarantee our
inductions. The second justification is that we can assume that something
will continue to happen because it has always happened before. To
Hume, this kind of reasoning is circular and lacks a foundation
in reason. Despite the efforts of John Stuart Mill and others, some
might argue that the problem of induction has never been adequately
resolved. Hume left the discussion with the opinion that we have
an instinctual belief in induction, rooted in our own biological habits,
that we cannot shake and yet cannot prove. Hume allows that we can
still use induction, like causation, to function on a daily basis
as long as we recognize the limitations of our knowledge.
Religious Morality Versus Moral Utility
Hume proposes the idea that moral principles are rooted
in their utility, or usefulness, rather than in God’s will. His
version of this theory is unique. Unlike his Utilitarian successors,
such as John Stuart Mill, Hume did not think that moral truths could
be arrived at scientifically, as if we could add together units
of utility and compare the relative utility of various actions.
Instead, Hume was a moral sentimentalist who believed that moral
principles cannot be intellectually justified as scientific solutions
to social problems. Hume argues that some principles simply appeal
to us and others do not. Moral principles appeal to us because they
promote our interests and those of our fellow human beings, with
whom we naturally sympathize. In other words, humans are biologically
inclined to approve and support whatever helps society, since we
all live in a community and stand to benefit. Hume used this simple
but controversial insight to explain how we evaluate a wide array
of phenomena, from social institutions and government policies to
character traits and individual behavior.
The Division of Reason and Morality
Hume denies that reason plays a determining role in motivating
or discouraging behavior. Instead, he believes that the determining
factor in human behavior is passion. As proof, he asks us to evaluate human
actions according to the criterion of “instrumentalism”—that is,
whether an action serves the agent’s purpose. Generally, we see
that they do not and that human beings tend to act out of some other
motivation than their best interest. Based on these arguments, Hume
concludes that reason alone cannot motivate anyone to act. Rather,
reason helps us arrive at judgments, but our own desires motivate
us to act on or ignore those judgments. Therefore, reason does not
form the basis of morality—it plays the role of an advisor rather
than that of a decision-maker. Likewise, immorality is immoral not
because it violates reason but because it is displeasing to us.
This argument angered English clergy and other religious philosophers
who believed that God gave humans reason to use as a tool to discover
and understand moral principles. By removing reason from its throne,
Hume denied God’s role as the source of morality.
Finding God in an Orderly Universe
Hume argues that an orderly universe does not necessarily
prove the existence of God. Those who hold the opposing view claim
that God is the creator of the universe and the source of the order
and purpose we observe in it, which resemble the order and purpose
we ourselves create. Therefore, God, as creator of the universe,
must possess intelligence similar, though superior, to ours. Hume
explains that for this argument to hold up, it must be true that
order and purpose appear only as a direct result of design. He points
out that we can observe order in many mindless processes, such as
generation and vegetation. Hume further argues that even if we accept
that the universe has a design, we cannot know anything about the
designer. God could be morally ambiguous, unintelligent, or even
mortal. The design argument does not prove the existence of God
in the way we conceive him: all-knowing, all-powerful, and entirely
beneficent. The existence of evil, Hume holds, proves that if God
exists, God cannot fit these criteria. The presence of evil suggests
God is either all-powerful but not completely good or he is well-meaning
but unable to destroy evil, and so not all-powerful.
The Bundle Theory of the Self
Hume asks us to consider what impression gives us our
concept of self. We tend to think of ourselves as selves—stable
entities that exist over time. But no matter how closely we examine
our own experiences, we never observe anything beyond a series of
transient feelings, sensations, and impressions. We cannot observe
ourselves, or what we are, in a unified way. There is no impression
of the “self” that ties our particular impressions together. In
other words, we can never be directly aware of ourselves, only of
what we are experiencing at any given moment. Although the relations
between our ideas, feelings, and so on, may be traced through time
by memory, there is no real evidence of any core that connects them.
This argument also applies to the concept of the soul. Hume suggests
that the self is just a bundle of perceptions, like links in a chain.
To look for a unifying self beyond those perceptions is like looking
for a chain apart from the links that constitute it. Hume argues
that our concept of the self is a result of our natural habit of
attributing unified existence to any collection of associated parts.
This belief is natural, but there is no logical support for it.
