SEP articles are written by individual academics, who often have peculiar writing styles. I suppose the editors try to curb the most extreme of peculiarities, but all sorts of quirks inevitably leak through. Archaism and grandiosity are especially common, since a lot of philosophers spend a lot of time poring through old books.
Wikipedia articles, on the other hand, tend to have a rather bland writing style, the average of all the people who contributed to an article.
Wikipedia articles, on the other hand, tend to have a rather bland writing style, the average of all the people who contributed to an article.