The word "we" can sometimes include the reader, for example in mathematical deductions.[citation needed]The acceptability of passive voice in scientific writing is inconsistent. It is not always wanted, but is sometimes encouraged. One reason that passive voice is used in scientific writing is that it is beneficial in avoiding first-person pronouns, which are not formally accepted in science.[7] It can be hard to make claims in active voice, that is, without the words, I" and "we".