If "doctrine" is defined as being the official teachings of the Church, then one cannot say that the LDS canon is doctrine, or what is written in the LDS canon is doctrine.
This is hardly logically obvious. All that is required here is that the LDS canon be considered itself a part of the class "official Church doctrine" and hence, subsumed within the larger doctrinal sphere comprising the entire doctrinal range of the Church' teachings.
More precisely, perhaps, that which is a part of the class of concepts known as "official Church doctrine" would be, not the scriptures per se, but
anything and everything within the scriptures that is doctrine, or doctrinally sound. Anything, by definition, within the four standard works that is doctrinal, remains just as doctrinal when classed as "official Church doctrine" as when simply classed as New Testament doctrine, or Book of Mormon doctrine, or Book of Abraham doctrine, or whatever.
The crux of the matter then, is truth, not its provenance. So long as that provenance is divine in nature and has come through the channels of legitimate priesthood authority, whether it is found in the scriptures, in General Conference addresses, First Presidency messages in the
Ensign, BYU devotionals, official proclamations, Church educational materials, or anywhere else, if the First Presidency and the Twelve, as a body, have taught it, support it, and it is published by the Church and used in teaching and training, it can be considered doctrine.
The final confirmation is, of course, the witness of the Holy Ghost, which allows us a pure, direct knowledge of the truth, or untruth, of any principle.
For example, the revealed canonical Word of Wisdom teaches that beer--mild drinks made with barley--is good. However, the current doctrine (teachings of the Church) teaches that all drinks containing alcohol are to be avoided.
But there is a single feature or aspect to this that applies equally to all such drinks, which you have already mentioned - alcohol. This is one of the primary purposes of modern, continuing revelation through living prophets: the continuing clarification and definition of already existing doctrines and counsel.
Alcohol is the defining characteristic the WoW seeks to address, not any particular alcoholic beverage. As culture and social context changes, Church doctrines are refined, expanded and clarified as needed. Without contemporary prophets, this process becomes one of the mere theoretical extraction of doctrine through scriptural exegesis
To say that the doctrine "resides" in the scriptures, but can only be known as they are interpreted or changed by current Church leaders, leaves discussion of doctrine being inherently in the scriptures a vacuous and hollow point.
I'm not following this. Why cannot doctrine be both
inherently within the scriptures and
inherently within the revealed words of living prophets, as well as
inherently within each individual as he/she receives a witness of the truth of principle x, y, and z, but at different times and to different degrees as the gospel develops (line upon line...)?
I see no reason why doctrine cannot reside inherently within the scriptures, while at the same time still needing clarification and elucidation by living, authorized interpreters for the body of the Church. If the words, ideas, and teachings of the scriptures were of an overwhelmingly obvious, unambiguous, and conceptually precise kind, one might hypothetically argue that there would be no need for any further clarification by divinely authorized "revelators" authorized to make such clarifications and refinements. That, however, has clearly never been the case.
The doctrine, in other words, "resides" both in the scriptures and in the living oracles because both the scriptures and the words of the living oracles have their origin in the same source. The true, or correct understanding of the doctrine resident in the scriptures,
is not resident in any particular individual, or group of individuals, and hence, the need for living prophets and contemporary "official doctrine" within the restored Kingdom.
In other words, you cannot point to the LDS canon and say that someone can just turn to them to understand the doctrine (teachings) of the Church.
Correct, as Joseph found out with the Bible in his own time.
As you have pointed out, by just going to the scriptures a myriad of different, contradicting, and voided teachings can be found. Rather for someone to find out what the Church's doctrines are, they cannot appeal to the LDS canon, but instead have to go to sanctioned interpretations by current Church leaders. Because they cannot go to scripture, but must to go to official (published) interpretations, the only source for doctrine is in the official publications. This is pretty simple logic.
But weak logic, and demonstrative of a misunderstanding of the broader spectrum of LDS doctrine itself.
The four standard works are all official LDS publications, and hence, doctrinally established. The problem of interpretation resides in the individual, not in the Church (essentially, the First Presidency and Quorum of The Twelve unitedly) and hence, official interpretations and clarifications of scriptural teachings are there for the membership of the Church in a public way, as a safe doctrinal harbor for those with a greater need to be taught directly as well as for those who already understand but need, as all of us do, the witness and reassurance (as well as various clarifications and/or expansions) of Special Witnesses of Christ in our very own age.
However, each individual is quite capable, through the endowment of the Gift of the Holy Ghost, and through living righteously, of acquiring the correct interpretation of any teaching for himself through personal study, reflection, and prayer. This does not, however, happen in a vacuum. We need to be taught, and we need the teachings of the Brethren for both the generation of new ideas that will lead us to our own correct understandings of the scriptures, as well as for clear, concise, and unambiguous testimony as to what is right, what the Lord wants us to be doing, and in what manner he wants us to be doing it at a particular time.
There is public revealed teaching, for the church as a body, and private revelation and learning, for each individual within the Church. Correct doctrinal understanding is inherent in the ultimate source of truth with respect of both forms of reception of knowledge, public and private, and that is the Holy Spirit, and hence, correct "official doctrine" is, properly,
inherent within the Church per se.
It is the calling and authority of the Brethren to teach revealed doctrine and principle to the people publicly and in public venues
for the Church. We receive revelation for ourselves and others in our immediate environment. Much of this revelation will, of course, overlap. Individuals may receive much revelation regarding the Church, but are not authorized to teach publicly what has not been yet taught publicly by the Lord's authorized servents.