Proverbs 20:18

Every purpose is established by counsel: and with good advice make war.

Every purpose is established and made firm by counsel, so that plans become stable through advice. The verse thereby shows the excellence of prudent counsel and teaches the wisdom of valuing and seeking good advice, because wise advice is needed when making decisions. Its direction to make war with good advice means that decisions about war in particular require wise counsel. The best and wisest men sought prudent counsellors, whose judgment and knowledge gave strength and stability to whatever cause they supported.

A person should hold his own opinion based on facts and strengthened by correct reasoning, and in religious matters should be established in his own mind. The way to be stable and firm is first to know all that relates to a matter, to be fully informed and thoroughly acquainted with all its relations and bearings, and then to decide unalterably and firmly. The most fitting and certain means to that firm decision is obtaining the best, ablest, and most prudent advice.