研究張君勱的思想所碰到的最大困難是它的嬗變、混淆、甚至前後矛盾。造成這個現象的原因並不只是因為他的思想成分相當複雜，包涵中國傳統儒家（尤其是理學）、西方（尤其是德國）思想，也同時由於他無法清楚表明他在此一時或彼一時，甚至同一時期要信從何種互為衝突的思想。因此，當他所處的思潮在短期內有巨大轉移時，他的思想中的嬗變、混淆或矛盾現象即跟著加深。這個現象在研究張君勱的論著中，常有意無意被忽視，因此格外值得強調。 本文的目的在於指出張君勱思想裡的種種嬗變、混淆或矛盾也一樣出現在他對歐戰的看法上。 按時序先後簡言之，他對歐戰第一個看法是把它當做鞭策中國往富強之路之借鑑（可稱之為「富國強兵」之鑰）；第二個看法是把它當做中國躋身世界之林的機會（可稱之為「對德、奧宣戰」之必要）；第三個看法是把它當做歐洲文明危機與社會主義到來之諍言（可稱之為「社會主義」之講求）；第四個看法是在《國憲議》中把社會主義與中國文明復興之契機連在一起（可稱之為「社會主義和儒家世界」之未來）。第五個看法可看成是「科玄論戰」的問題，已於他文相當詳細討論了，故本文主要談論前四個看法。 張君勱對歐戰的第一個看法和第四（第五）個看法簡直是南轅北轍，完全相反。在第一個看法裡，他對科學應用，更遑論科學精神，沒有絲毫的批判。在第四（第五）個看法裡，他對科學精神，更遑論科學應用，有極強烈的批判。在第一個看法裡，他對社會主義雖有欣賞，但仍止於理解和注意的階段，到了第四（第五）個看法時，則一反過去對科學應用之歌頌，轉而歌頌社會主義。 至於介乎其間的第二、第三個看法，以第二個看法受時空的限制最大，因為它大致限於權衡時局的判斷；第三個看法則已含有第四個看法之雛型，雖它也與時局有密切關連。 綜觀張君勱的四個看法，我們雖可以辯護說，其嬗變皆有當時的情勢和思潮的軌跡可尋，但問題是，張君勱在提出一看法時所想捕捉的情勢和思潮並不一定就是主流，所以後來會有看法上的嬗變。但嬗變後的看法又被緊接著而來的新情勢和思潮的發展所推翻。若以思想家的標準來看，則顯示張君勱並沒有先見之明。但就張君勱抱持每個看法之強度與變化速度之快，以及他後來的悔悟之深而言，仍是值得注意，也很值得吸取教訓。

　　　　　One of the big difficulties in the study of the thought of Chang Chun-mai lies in its variety, confusion and even contradictions. The causes for these are not simply to be attributed to the complicated elements that he derived from both traditional Chinese Confucian (especially new Confucian) and Western (especially German) thoughts, but also that he was not able to make clear what he wanted to hold onto among various conflicting thoughts. Thus, when he was faced with tremendous change in trends of thought in a short period, the varying, confusing or even contradictory state tended to deepen. This is a point that has been neglected unintentionally or even on purpose by scholars in the study of Chang's works, and thus deserving emphasis. The purpose of this article is to show that the sort of variety, confusion or contradictions that are to be found in Chang's thought are also found in his views on WWI. In rough chronological sequence, and in brief, Chang's first view on WWI was to regard it as a god-sent golden message and lesson to impel China to seek out ways and means to become a rich and powerful nation (this may be called “the key to the nation's strength and power); his second view on WWI was to regard it as an opportunity to join the world of nations with equal status and dignity (this may be called “the necessity to declare war on Germany and Austria”); his third view on WWI was to regard it as a crisis of European civilization and as a harbinger to socialist society (this may be called “the advocacy of ‘socialism’”); his fourth view on WWI is contained in his book “On National Constitution” informing an attempt to collapse socialism with the chance to revive China's civilization through regeneration of Confucianism (this may be called “the future of socialism and Confucian world”). His fifth view on WWI can be regarded as the question of “the polemic on science and metaphysics”. This article only deals with the first four views, as the last one has already been dealt with in another article. Chang's first view on WWI is in diametrical opposition to his fourth view on WWI, not to say the fifth one. In his first view on WWI, he was not critical at all about the application of science, not to mention the spirit of science. While in his fourth view on WWI, not to say the fifth one, his criticism of both the application and the spirit of science reached its peak. Moreover, in his first view on WWI, though he was appreciative of socialism, this stopped short at the stage of attention and understanding, but when he reached his fourth and fifth views on WWI, he had reversed his praise of the application of science for a glorification of socialism. We notice that between the two contradictory views on WWI, there were his second and third views on WWI. His second view on WWI was confined to an larger extent than the other three views by the contingency of the time and place, for obvious reasons, and was thus a sort of judgment intended to take full account of the circumstances China was then in. So was his third view on WWI, though it already contained fledging elements of the fourth view on WWI. In sum, though we may argue that the changes as found in Chang's four views on WWI were all attributable to the situation and currents of thought of the time, the question remains that there was no necessity accountable for Chang's holding those four views on WWI, in fact, as the development of the situation and currents of thought unfolded, Chang's views could not endure for long, each being qualified, replaced, or contradicted either by the one immediately succeeding it or by a combination of those he subsequently held. As judged by the standard of a thinker, it is shown that Chang did not have foresight on what were to come.