These two notions of present and of past time, being expressed by a change of form, are true tenses. If there were no change of form, there would be no change of tense. They are the only true tenses in our language. In _I was beating_, _I have beaten_, _I had beaten_, and _I shall beat_, a difference of time is expressed; but as it is expressed by _a combination of words_, and not _by a change of form_, no true tenses are constituted. § 294. In Greek the case is different. Τύπτω (typtô) = _I beat_; ἔτυπτον (etypton) = _I was beating_; τύψω (typsô) = _I shall beat_; ἔτυψα (etypsa) = _I beat_; τέτυφα (tetyfa) = _I have beaten_; ἐτετύφειν (etetyfein) = _I had beaten_. In these words we have, of the same mood, the same voice, and the same conjugation, six different tenses; whereas, in English, there are but two. The forms τέτυφα and ἔτυψα are so strongly marked, that we recognise them wheresoever they occur. The first is formed by a reduplication of the initial τ, and, consequently, may be called the reduplicate form. As a tense it is called the perfect. In the form ἔτυψα an ε is prefixed, and an σ is added. In the allied language of Italy the ε disappears, whilst the σ (s) remains. Ἔτυψα is said to be an aorist tense. _Scripsi_ is to _scribo_ as ἔτυψα is to τύπτω. § 295. Now in the Latin language a confusion takes place between these two tenses. Both forms exist. They are used, however, indiscriminately. The aorist form has, besides its own, the sense of the perfect. The perfect has, besides its own, the sense of the aorist. In the following pair of quotations, _vixi_, the aorist form, is translated _I have lived_, while _tetigit_, the perfect form, is translated _he touched_. _Vixi_, et quem dederat cursum Fortuna peregi; Et nunc magna mei sub terras ibis imago.--_Æn._ iv. Ut primum alatis _tetigit_ magalia plantis.--_Æn._ iv. § 296. When a difference of form has ceased to express a difference of meaning, it has become superfluous. This is the case with the two forms in question. One of them may be dispensed with; and the consequence is, that, although in the Latin language both the perfect and the aorist forms are found, they are, with few exceptions, never found in the same word. Wherever there is the perfect, the aorist is wanting, and _vice versâ_. The two ideas _I have struck_ and _I struck_ are merged into the notion of past time in general, and are expressed by one of two forms, sometimes by that of the Greek perfect, and sometimes by that of the Greek aorist. On account of this the grammarians have cut down the number of Latin tenses to _five_; forms like _cucurri_ and _vixi_ being dealt with as one and the same tense. The true view is, that in _curro_ the aorist form is replaced by the perfect, and in _vixi_ the perfect form is replaced by the aorist.