<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-07-25</periodOfReport><notSubjectToSection16>1</notSubjectToSection16><issuer><issuerCik>0000046989</issuerCik><issuerName>HERCULES INC</issuerName>        <issuerTradingSymbol>HPC</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001014051</rptOwnerCik><rptOwnerName>TROUBH RAYMOND S</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>1313 N. MARKET ST.</rptOwnerStreet1><rptOwnerStreet2></rptOwnerStreet2><rptOwnerCity>WILMINGTON</rptOwnerCity><rptOwnerState>DE</rptOwnerState><rptOwnerZipCode>19894</rptOwnerZipCode><rptOwnerStateDescription></rptOwnerStateDescription></reportingOwnerAddress><reportingOwnerRelationship><isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value><footnoteId id="F1" /></securityTitle><transactionDate><value>2003-07-25</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>A</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>636</value></transactionShares><transactionPricePerShare><value>11</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>11202</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock</value><footnoteId id="F2" /></securityTitle><transactionDate><value>2003-07-25</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>D</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>700</value></transactionShares><transactionPricePerShare><value>12</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>11202</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock</value><footnoteId id="F2" /></securityTitle><transactionDate><value>2003-07-25</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>D</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>562</value></transactionShares><transactionPricePerShare><value>9.07</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>D</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>11202</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock</value><footnoteId id="F3" /></securityTitle><transactionDate><value>2003-07-25</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>D</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>5120</value></transactionShares><transactionPricePerShare><value>7.616</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>11202</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">Grant of Restricted Stock Units which when vested will be payable in cash</footnote><footnote id="F2">Forfeit of RSUs.</footnote><footnote id="F3">Forfeiture of NEDSAP restricted stock</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>Raymond S. Troubh</signatureName><signatureDate>2003-07-29</signatureDate></ownerSignature></ownershipDocument>

