###### Structure, Consistency and Consequences Before we proceed it will be very helpful for us to take a brief detour into the realm of argument structure, logical content and consequences. We'll be referencing these quite heavily when we critique Moravec's argument. Let us start with structure. Arguments are *constructed*, they are built up, they are created. They have a *structure*. We can think of them as an interconnected network of ideas that build on one another. Some are initial assumptions, some are logical deductions from those assumptions, and so on. But we can roughly think of a network such as the one below. %%TODO: image%% %%TODO: definitely need a good example here%% There is no need to be prescriptive or overly constraining for our purposes on just what structure an argument must have. Sometimes it resembles a tree and other times more of a cluster of interconnected ideas. But we should recognize that depending on the specific structure utilized, certain elements of the argument will bear more *load* than others. We can call these *load bearing* elements. These elements are quite easy to recognize for many claims and consequences depend on them. %%TODO: image%% For example, consider the theory of evolution by natural selection. One of the most load bearing elements in this theory is the idea of random genetic variation. This is what allows the mechanism of natural selection to take off—without random variation we would be left with stasis. It is therefore integral to explain the adaptations and diversity of life we see around us. Also notice that this structure must be *consistent*, meaning that the entire structure must be able to be true at the same time. Otherwise, the entire argument is rendered *inconsistent*. One cannot just wish this problem away. A contradiction in your argument is a glaring error—it means it is not even satisfactory *on it's own terms*, nevertheless when subjected to the criticism of other arguments. Of course you can tweak, update or overhaul the argument to try and make it consistent. But insofar as one wishes to construct strong arguments, inconsistency is a death sentence. Let us use another example. This time consider the following argument: "All opinions are equally valid. Therefore, you're wrong to say that some opinions are better than others." This argument undermines itself by being internally inconsistent—both elements cannot possibly be true at the same time. In other words, it both accepts and rejects the idea that some opinions can be better than others—a totally incoherent position. %%TODO: image%% Logic is about *truth preservation*. While we are fallible we still are attempting to iterate towards truth over time by iteratively removing error from our ideas.