On Principle and InterestIf you believe in principle, then you accept implication and inference (even necessary ones). A principle is a fundamental truth from which other laws or behaviors are derived. Upon understanding a principle, we recognize a variety of applications that derive from it. Yet the applications themselves might be unstated and we must figure out the specifics. Hebrews 5:14 speaks of the mature who have their senses trained to discern good and evil. Discernment is the ability to see a principle for what it is and make the proper applications from it. Mature people don't need everything spelled out. They can grasp a principle and make applications appropriately. That is, they are able to draw the needed conclusions from the principles about what's right or wrong. To do such requires the ability to infer from what the principles imply.
It is not uncommon, in discussions about authority, to see the concept of "necessary inference" taken to task. Yet the same ones who will take the concept to task may also speak of principles guiding their behavior. They don't realize that they are sawing off the branch upon which they are sitting. There is no living by principle if inferences have no binding power at all, for proper applications of any principle will necessarily involve those pesky inferences. Try stating a principle without making any specific, implied applications and see how that goes over. The principle would just be an empty idea with no real world application.
Many precepts are stated in a way that leaves us to work through the proper applications. For example, we are told, "love your enemies, and do good, and lend, expecting nothing in return; and your reward will be great, and you will be sons of the Most High; for He Himself is kind to ungrateful and evil men. Be merciful, just as your Father is merciful" (Luke 6:35-36). Yet how is all of this to be carried out? We can define love and mercy the way we wish (subjective and self-willed), or we can dig further into Scripture and see exactly how God showed love and mercy. Then, we can see how to make applications in our own age. All of this requires inferring from then to now and from God's actions to ours. Without inference, there is no modern application.
Once again we see the inescapable principles of authority. What God has told us, shown us, and implied are on every page. We cannot rightly say, "Only commands are binding," for even then we will have crippled our abilities to make modern applications of those commands (again, try applying an ancient command to a modern context without inferring anything about how that command should be contextualized).
Without a doubt, inferences can be unnecessary and result in an abuse of a text. However, the fact that an abuse can take place does not invalidate the point. Such just drives home the need to be careful in drawing conclusions and making applications. The interpretation of Scripture needs to be attended by good reason and a great care for context. That is why this particular subject is important. If we care about principle, we'll care about proper reasoning from the principle to the applications.