I have just realized I miss out one of the fallacies committed when I offered a rebuttal of Wenxian's post here and here. This is the logical fallacy of total concept transfer, in which the conclusions of a concept from one area is applied similarly onto another area en toto, without consideration of the differences between the two areas.
This logical fallacy belongs to the same class as the logical fallacies of equivocation and amphiboly, as all three fallacies are based on some type of equivocation. The fallacy of equivocation occurs when the meaning of one word used in two different contexts are equivocated, the fallacy of amphiboly occurs when the meaning of one phrase used in two different contexts are equivocated (or when one phrase can have two different meanings), and the fallacy of total concept transfer occurs when the meaning and application of one principle/ theory from one discipline/area is applied in the same manner (equivocated) to another discipline/area. The different fallacies are ilustrated as shown:
Fallacy of equivocation:
My wife drove me up the wall yesterday. Therefore, my wife can drive the car. (Equivocation of the word 'drive')
Fallacy of amphiboly:
I want to study ants in my car. (So is the person studying ants while he is in his car, or is the person studying ants which are found in his car? — Equivocation over the phrase 'study ants in my car')
Fallacy of total concept transfer:
Objective truth exists, since the statement 'there is objective truth' is either true or not true. If it is true, then objective truth exists; if it is not true, then it is objectively true that 'objective truth does not exist', which is a contradiction and thus absurd. (Consequentia mirabilis) Therefore, objective truth exists and relativism is wrong.
Now, I have tasted and am convinced that this cake is nice. Since there is objective truth, the fact that this cake is nice must be objectively true, and therefore no one can say that this cake is not nice without denying the truth.
OK, so what exactly is the fallacy committed in Wenxian's post? In that post, the principle of the regulative principle of worship, which is only linked to worship by the way, is taken out of its doctrinal context and applied in the same manner onto the doctrine of baptism. Worship and baptism are two different areas of the Christian life, and each of them have specific passages from Scripture addressing them both. As both of them are scriptural practices, the practice of both of them must be found within the pages of Scripture, and thus the principle of Sola Scriptura must be applied to the practice of both of them, as with any other practice which Christians do. The regulative principle, however, is something which is only liked with worship and therefore, to take this principle, rip it out of its biblical area of application, and applying it to baptism is to commit the fallacy of total concept transfer.
In closing, let me give one last example of the fallacy of total concept transfer, courtesy of Dr. James R. White as stated in his blog here:
Roman theology is Arian. Why? Because its man-centered sacramental system denies the Lordship of Christ, hence his deity, in providing perfect salvation for the elect. While the Scriptures emphasize Christ's ability, man-centered religious systems like Rome emphasize man's ability and reduce Christ to a mere helper, one who tries, but often fails, to accomplish His intentions. Since God cannot fail, and Rome presents a Savior who tries, but fails, to save, then Rome is Arian. (The fallacy is committed when one applies a concept in Christology and applies it to the area of Soteriology)