Misconception
Some advaitins claim:
Advaitin holds all the scriptural literature to have Advaita as the supreme purport.
They mine verses from pAncharAtra and shaivAgama to show that they propound shAnkarAdvaita.
However this is wrong.
For a proper intro to shaivAgamas one should read prakaraNa texts like siddhAnta-prakAshikA or shaiva-siddhAnta-sArAvali.
shankara’s opinion
Picking random verses and befuddling readers is not shankara-level. Shankara clearly understood and stated that pAncharAtra’s supreme purport contradicts his views. Now, he would not be opposed to taking “परमतम् अप्रतिषिद्धम् अनुमतं भवति”, but he would definitely not claim “all shAstra-s teach advaita as I do " - that seems to be the weird game of misguided followers.
“Everything is God. Doing pUja to him is a good idea.” - Is this is the only “supreme purport” of pAncharAtra as understood by shankara (as claimed by some)? Isn’t it a silly thing to have to “prove”? But no - he was not a charlatan.
In his brahma-sUtra bhAShya, he is arguing that: On account of the impossibility of the origination (of the individual soul from the highest Lord, the doctrine of the Bhāgavatas cannot be accepted). This jIveshvara separation he implies to be the pAncharAtra doctrine. He emphasises non-svarUpaikya by questioning distinction of the 4 vyUha-s (if svarUpaikya is admitted there) from everything else (ब्रह्मादि-स्तम्ब-पर्यन्त).
Yet, his “followers” try to mine quotes to “show” that pAncharAtra declared advaita, svarUpaikya etc..
madhusUdhana-sarasvatI
Having described, among many other texts, pAncharAtra and pAshupata, madhusUdana-sarasvati concludes:
सर्वेषां प्रस्थान-कर्तॄणां मुनीनां
विवर्त-वाद-पर्यवसानेनाद्वितीये परमेश्वर एव प्रतिपाद्ये तात्पर्यम् ।
… किं तु बहिर्-विषय-प्रवणान्
आपाततः पुरुषार्थे प्रवेशो न सम्भवतीति नास्तिक्य-वारणाय
तैः प्रकार-भेदाः प्रदर्शिताः ।
…
तत्र तेषां (मुनीनां पूर्वोक्तं) तात्पर्यम् अबुद्ध्वा
वेद-विरुद्धे ऽप्य् अर्थे तात्पर्यम् उत्प्रेक्ष्यमाणास्
तन्-मतम् एवोपादेयत्वेन गृह्णन्तो जना
नाना-पथ-जुषो भवन्तीति सर्वम् अनवद्यम् ॥
Some advaitins take this to mean:
The Akhanda Tatparya of all the shastras is in advaita only as all the rishis believed in it. However, due to adhikara bheda, rishis propagated different doctrines in different shastras based on the sanskara and pravrtti of various jeevas.
MS, having contrasted distinctions of various systems (eg. pariNAmavAda vs ArambhavAda vs vivarta-vAda etc..),
obviously did not say that all shAstra-s preach advaita.
He is saying that their authors personally believed in advaita + vivartavAda,
however, to prevent nAstikya and such, they made up various shAstras.
This misinterpretation is perhaps due to the below misreading:
“तत्र तेषां (शास्त्राणां) तात्पर्यम् अबुद्ध्वा”
instead of
तत्र तेषां (मुनीनां पूर्वोक्तं) तात्पर्यम् अबुद्ध्वा
MS can be said to think that the shAstras intend to teach “vivartavAda and svarUpaikya is correct” by teaching “vivartavAda and svarUpaikya is wrong”, as a trick to improve the capacity of the seeker (aka chittashuddhi). However, some “followers” claim that the said shAstras directly teach svarUpaikya by various out-of-context quotes. That contradicts MS.
Will someone now quote sarvadarshanasangraha and claim that it’s author mAdhavAchArya also held that all shAstra-s preach shANkarAdvaita? :-P