Samkhya Karika 51

ऊहः शब्दोऽध्ययनं दुःखविघातास्त्रयः सुहृत्प्राप्तिः ।
दानं च सिद्धयोऽष्टौ सिद्धेः पूर्वोऽङ्कुशस्त्रिविधः ॥ ५१ ॥

ūhaḥ śabdo’dhyayanaṁ duḥkhavighātāstrayaḥ suhṛtprāptiḥ ।
dānaṁ ca siddhayo’ṣṭau siddheḥ pūrvo’ṅkuśastrividhaḥ ॥ 51 ॥

ūhaḥ=reasoning; śabdaḥ=oral instruction; adhyayanaṁ=study; duḥkha=suffering; vighātāḥ=suppression; trayaḥ=three; suhṛtprāptiḥ=acquisition of friends (suhṛd); dānaṁ=charity or purity; ca=and; siddhayaḥ=siddhis (attainments); aṣṭau=eight; siddheḥ=of the attainment; pūrvaḥ=before; aṅkuśaḥ=obstacles; trividhaḥ=three-fold

The eight attainments are: reasoning, oral instruction, study, suppression of the three-fold suffering, acquisition of friends, purity (or charity). The three mentioned earlier (ignorance, disability and contentment) are obstacles to success.