Aside from the fact that this verse is more often than not cherry-picked out of the context of the book of Ecclesiastes and made to say the opposite of what it really means (more on this in a minute), the idea of never being able to resolve debates because we haven't done so in the past is a variation of the logical fallacy known as the "Gambler's Fallacy." Author Joel McDurmon explains:
The Gambler's Fallacy occurs when an event involves more than one possible outcome, and makes the mistake of assuming a particular outcome will occur based on the results of past experience. It appears in different varieties. A common example involves a "Gambler" who assumes that since every pull of the slot machine lever has resulted in nothing so far, therefore the next pull should win big. When someone watches a lucky streak or sequence of "beating the odds," and assumes that the streak must soon end, they also commit the fallacy...The fact that the fallacy can appear in either form—assuming the continuation of a streak, or the end of one—testifies to the fallaciousness of the idea in general. Either outcome remains just as possible, and thus to assume either way based on past outcomes commits the fallacy. 
In other words, the current event under consideration is not based on the success or failure of similar events in the past. Arguing that a certain theological dispute is beyond resolution because we haven't been able to solve it up to this point is not a valid argument. In fact, Solomon incorporates a version of the gambler's fallacy into his writing in the book of Ecclesiastes. It has been pointed out that what Solomon is actually doing in Ecclesiastes is using his own prescribed apologetic method from Proverbs 26: 4-5, which states: "Do not answer a fool according to his folly, or you will also be like him. Answer a fool as his folly deserves, that he not be wise in his own eyes." In Ecclesiastes, Solomon is taking the ultimate assumption of the unbeliever—i.e. there is no God—to its logical conclusion. In reality, Solomon is showing the complete futility of life without God, not the futility of life in general.
Ecclesiastes has been understood as an apologetic work, that is, an attempt to recommend faith in God by way of answering negative arguments. As such an attempt, the book often seems to express a secular point of view, arguing that life is meaningless. In the face of such arguments the writer comes to the conclusion that faith in God is the only avenue to satisfaction in life...The book is God's wise counsel to those who know His ways but have found them perplexing and troubling. 
The major reason we miss what Solomon is doing with his book is because we don't read it "as a book." Like the rest of the Bible, we read it in segments—a little bit here, a little bit there—rather than straight through as one complete writing. One of the scourges of modern Bibles is the division into chapters and verses. Although this convention greatly helps in referencing and finding certain passages in Scripture, it also has the unintended consequence of turning the Bible into a religious book of sayings. Modern Christians tend to forget that the Bible is a "book of books," and not simply a book of wisdom. While it certainly contains wisdom—it is the revelation of God—it is not a book that we can simply flip to any page and start reading. The Bible is communicating truth to us, but it is communicating truth in relation to the rest of the book. Every book and epistle in the Bible is meant to be read in light of the rest of the book, not in isolation from it. No part of the Bible can stand on its own; God's Word is the whole Bible, not certain portions of it.
This segmenting of the Bible is also the cause of many of the disputes and disagreements that arise in theological discussions. Misunderstandings are often a direct result of readers importing an understanding into the Bible based on a verse or two, rather than doing the hard work of exegesis, allowing the Bible to speak to and teach us in its entirety.
One of the classic disputes in church history is the written debate between George Whitefield and John Wesley over election/predestination. If you haven't read Whitefield's letter to Wesley, you really should take the time to read it (and you have, why not read it again). I will reprint Whitefield's letter on Wednesday, but in the meantime, you have some homework to do. First, read Iain Murray's introductory article. Second, read John Wesley's sermon entitled "Free Grace." It was this sermon that prompted Whitefield's response letter.
By reading these historical documents, I want readers to notice two important things. First, notice that Whitefield and Wesley both understood that they were arguing an age-old debate. Neither had any delusion that they were the first to believe the way that they did, neither did they believe that they were offering the definitive word on the topic. Both understood that the Bible held the true answer, and they both appeal to biblical revelation as the authoritative source. While their theology may have separated them, their mutual admiration for each other remained steadfast. In fact, when asked if he would see Whitefield in heaven, Wesley replied, "No, George Whitefield will stand so near the throne that one like me will never get a glimpse of him."  Theological division should never lead to personal division among believers.
Second, notice how easy it is to be convinced in the rightness of an interpretation because of preconceived ideas, rather than allowing the Bible to speak in its fullness. Due to his Arminianism, Wesley had a belief about the nature of God that he brought to the Bible, and believed he found biblical support of this belief. Because he was first convinced about what God was like, he was unable to objectively examine his own beliefs in the light of the Bible. In other words, Wesley's belief in the unconditional love of God for every person on earth, led him to make certain conclusions that the Bible itself doesn't (and cannot) teach. Whitefield's letter makes this point plain by keeping his response focused on the Bible, rather than emotional pleas and speculation about God is like. This historic heated debate should inform and provide modern believers with an example of how to do theology—both in the church and outside of it.
 Joel McDurmon, Biblical Logic: In Theory and Practice (Powder Springs, GA: AV Press, 2009), 351-352.
 Reformation Study Bible (Orlando, FL: Ligonier, 2005), 923.
 Caleb Thomas Winchester, The Life of John Wesley (London: Macmillan, 1906), 165.
Recommended further reading:
Amazing Grace: The History and Theology of Calvinism
R.C. Sproul: What is Reformed Theology?
Joel McDurmon: Biblical Logic-In Theory and Practice
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