_certo (certe) scio_[1] (Arch. 12. 32)—I know for a fact.
_probe scio, non ignoro_—I know very well.
_non sum ignarus, nescius_ (not _non sum inscius_)—I know very well.
_me non fugit, praeterit_—I am not unaware.
_quantum scio_—as far as I know.
_quod sciam_—as far as I know.
_hoc_ (not _tantum_) _certum est_—this much is certain.
_aliquid compertum habere_—to know a thing for certain.
_illud pro certo affirmare licet_—this much I can vouch for.
_mihi exploratum est, exploratum (certum) habeo_—I am quite certain on
the point.
_inter omnes constat_—it is a recognised fact.
_mihi persuasum est_[2]—I am persuaded, convinced.
_mihi persuasi_—I am persuaded, convinced.
_sic habeto_—convince yourself of this; rest assured on this point.
_persuade tibi_—convince yourself of this; rest assured on this point.
_velim tibi ita persuadeas_—convince yourself of this; rest assured on
this point.
_sic volo te tibi persuadere_—convince yourself of this; rest assured
on this point.
_addūcor, ut credam_—I am gradually convinced that...
_non possum adduci, ut (credam)_—I cannot make myself believe that...
_ex animi mei sententia_ (_vid._ sect. XI. 2)—according to my strong
conviction.
_suo iudicio uti_—to act in accordance with one's convictions.
[1] With _certe scio_, which is the form Cicero usually employs, the
certitude lies in our knowledge, _certum est me scire_; with _certo
scire_ the certitude lies in the object of our knowledge. _certo_
rarely occurs except with _scio_.
[2] Caesar occasionally uses _persuasum sibi habere_.