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                                                                     Exhibit 5.1


                      [Letterhead of Dorsey & Whitney LLP]

                                                                 August 27, 1999

ARIS Corporation
2229 112th Avenue N.E.
Bellevue, Washington 98004

            Re:  Registration Statement on Form S-4

Ladies and Gentlemen:

      We have acted as counsel to ARIS Corporation, a Washington corporation
(the "Company"), in connection with a Registration Statement on Form S-4 (the
"Registration Statement") being filed pursuant to Rule 462(b) under the
Securities Act of 1933, as amended, relating to the issuance by the Company of
shares of common stock of the Company, without par value (the "Common Stock"),
to the shareholders of fine.com International Corp., a Washington corporation
("fine.com"), in connection with the merger of fine.com with and into a wholly
owned subsidiary of the Company as described in the Registration Statement (the
"Merger").

      We have examined such documents and have reviewed such questions of law as
we have considered necessary and appropriate for the purposes of our opinions
set forth below. In rendering our opinions set forth below, we have assumed the
authenticity of all documents submitted to us as originals, the genuineness of
all signatures and the conformity to authentic originals of all documents
submitted to us as copies. We have also assumed the legal capacity for all
purposes relevant hereto of all natural persons and, with respect to all parties
to agreements or instruments relevant hereto other than the Company, that such
parties had the requisite power and authority (corporate or otherwise) to
execute, deliver and perform such agreements or instruments, that such
agreements or instruments have been duly authorized by all requisite action
(corporate or otherwise), executed and delivered by such parties and that such
agreements or instruments are the valid, binding and enforceable obligations of
such parties. As to questions of fact material to our opinions, we have relied
upon certificates of officers of the Company and of public officials. We have
also assumed that the Common Stock will be issued and delivered in exchange for
shares of common stock of fine.com as described in the Registration Statement.

      Based on the foregoing, we are of the opinion that the shares of Common
Stock to be issued by the Company pursuant to the Registration Statement have
been duly authorized by all requisite corporate action and, upon issuance and
delivery thereof in exchange for shares of common stock of fine.com in the
Merger as described in the Registration Statement, will be validly issued, fully
paid and nonassessable.

      Our opinions expressed above are limited to the laws of the State of
Washington.

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      We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement, to the incorporation by reference into the Registration
Statement of the form of our tax opinion addressed to the Company and fine.com
and to the incorporation by reference into the Registration Statement of the
references to our firm under the headings "The Merger--Material Federal Income
Tax Consequences", "The Merger Agreement--Conditions to the Completion of the
Merger" and "Legal Matters" in the Proxy Statement/Prospectus constituting part
of the Registration Statement.


                                    Very truly yours,


                                    /s/ DORSEY & WHITNEY LLP