論說文是書面語體中運(yùn)用得非常廣泛的一種文體，通常分為議論和論述兩種，是相對(duì)于散文中的記敘（Narration）和描寫（Description）而言的。其常見形式包括社科論著、論文、評(píng)論、演講、講座、報(bào)告等。論說文的文體特點(diǎn)主要有以下幾條：

　　1） 措詞嚴(yán)謹(jǐn)規(guī)范。論說文的功用主要在于對(duì)某一觀點(diǎn)進(jìn)行解釋、說明或闡述，因此，此類文章講求理性與邏輯性，在措詞上表現(xiàn)為正式語體的詞、大詞、抽象詞、外來詞用得較多，而絕少使用俚語俗語及過于口語化的詞，以體現(xiàn)其莊重、嚴(yán)謹(jǐn)?shù)奶攸c(diǎn)。

　　2） 句法及篇章結(jié)構(gòu)較為復(fù)雜。由于論述文旨在解析思想，闡發(fā)論點(diǎn)，辨明事理，展開論證，因此文章內(nèi)容往往比較復(fù)雜。為全面、慎密地表述自己的見解，避免片面、疏漏，論說文中往往長句、復(fù)雜句使用較多。另外論說文講究謀篇布局及條理層次，因而在篇章結(jié)構(gòu)上較為復(fù)雜，往往段落之間環(huán)環(huán)相扣，層層遞進(jìn)。除此之外，論說文還十分講究修辭，辭格上多用排比、遞進(jìn)、設(shè)問等，以增強(qiáng)文章的感染力和說服力。

　　下面一例節(jié)選自一篇論說文，它較為清晰地顯示了論說文體的主要特點(diǎn)：

Science and Ethics?

　　Science impinges upon ethics in at least five different ways.

　　In the first place, by its application it creates new ethical situations. Two hundred years ago the news of a famine in China created no duty for Englishmen. They could take no possible action against it. Today the telegraph and the steam engine have made such action possible, and it becomes an ethical problem what action, if any, is right. Two hundred years ago a workman generally owned his own tools. Now his tool may be a crane or steam hammer, and we all have our own views as to whether these should belong to shareholders, the State, or guilds representing the workers.

　　Secondly, it may create new duties by pointing out previously unexpected consequences of our actions. We are all greed that we should not run the risk of spreading typhoid by polluting the public water supply. We are probably divided as to the duty of vaccinating our children, and we may not all be of one mind as to whether a person likely to transmit club foot or cataract to half his or her children should be compelled to abstain from parenthood.

　　Thirdly, science affects our whole ethical outlook by influencing our views as to the nature of the world-in fact, by supplanting mythology. One man may see men and animals as a great brotherhood of common ancestry and thus feel an enlargement of his obligations. Another will regard even the noblest aspects of human nature as products of a ruthless struggle for existence and thus justify a refusal to assist the weak and suffering. A third, impressed with the vanity of human efforts amid the vast indifference of the universe, will take refuge in a modified epicureanism. In all these attitudes and in many others there is at least some element of rightness.

　　Fourthly, in so far as anthropology is becoming scientific, it is bound to have a profound effect on ethics by showing that any given ethical code is only one of a number practiced with equal conviction and almost equal success; in fact, by creating comparative ethics. But, of course, any serious study of the habits of foreigners, whether scientific or not, had this effect, as comes out plainly enough in the history of ancient Greek ethics. Hence science is not wholly responsible for the ethical results of anthropology.??