Truth actually can be gained by implication. Logical implications are facts. They are nothing more than the full unfolding of facts which are already implied within what it explicitly stated.
For example, if I say that an apple costs $1 and you reply that you only have .75 cents - the logical implication is that you cannot afford the apple. Even though that's not what you explicitly said, it is logically implied.
Or to take another example from Math, 5 is the logical implication of (2+3).
Taking this to Scripture, the Bible only says (in the 10 commandments) "Thou shalt not steal". But what if you were to say: "Well, am I allowed to cheat on my taxes?" The answer, of course, is no. Because Thou shalt not cheat on your taxes is implied in thou shalt not steal.
If you get rid of logical implication then it will be almost impossible to apply Scripture to our lives at all. We'll never be able to arrive at the doctrine of the Trinity, etc...